Affected versions

• Firefox 76.0.1
• Firefox 77.0b3
• Latest Nightly 78.0a1

Affected platforms

• Windows 10 64bit
• Ubuntu 18.04 64bit

Unaffected platforms

• macOS 10.15.5 beta

Steps to reproduce

1. Start Firefox
2. Go to https://www.windy.com/
3. Focus on anything that's blue (issue can be seen more clearly)
4. Scroll in/out

Expected result

• No visual glitches can be seen

Actual result

• There can be seen some lines flashing on the map during zooming

Regression range

• First bad: f32d7f9eb04f365d4536659ac14f4a4b1819b5d6
• Last good: 91b3fc6f5fa0c418db43b4154f90a8040f97ad52
• Pushlog: https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=91b3fc6f5fa0c418db43b4154f90a8040f97ad52&tochange=f32d7f9eb04f365d4536659ac14f4a4b1819b5d6
• Potential regressor: Bug 1587713 - Remove the late blob rasterization code path

Additional notes

• about:support:

Application Basics
------------------

Name: Firefox
Version: 78.0a1
Build ID: 20200510092917
Distribution ID:
Update Channel: nightly
User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Firefox/78.0
OS: Windows_NT 10.0
Launcher Process: Enabled
Multiprocess Windows: 1/1 Enabled by default
Remote Processes: 7
Enterprise Policies: Inactive
Google Location Service Key: Found
Google Safebrowsing Key: Found
Mozilla Location Service Key: Found
Safe Mode: false

Crash Reports for the Last 3 Days
---------------------------------

Nightly Features
----------------

Name: DoH Roll-Out
Version: 1.3.0
ID: doh-rollout@mozilla.org

Name: Firefox Screenshots
Version: 39.0.0
ID: screenshots@mozilla.org

Name: Form Autofill
Version: 1.0
ID: formautofill@mozilla.org

Name: Web Compat
Version: 10.1.2
ID: webcompat@mozilla.org

Name: WebCompat Reporter
Version: 1.3.0
ID: webcompat-reporter@mozilla.org

Remote Processes
----------------

Type: Web Content
Count: 3 / 8

Type: Extension
Count: 1

Type: Privileged About
Count: 1

Type: GPU
Count: 1

Type: Socket
Count: 1

Extensions
----------

Name: Amazon.com
Version: 1.1
Enabled: true
ID: amazondotcom@search.mozilla.org

Name: Bing
Version: 1.1
Enabled: true
ID: bing@search.mozilla.org

Name: DuckDuckGo
Version: 1.0
Enabled: true
ID: ddg@search.mozilla.org

Name: Google
Version: 1.0
Enabled: true
ID: google@search.mozilla.org

Name: Twitter
Version: 1.0
Enabled: true
ID: twitter@search.mozilla.org

Name: Wikipedia (en)
Version: 1.0
Enabled: true
ID: wikipedia@search.mozilla.org

Security Software
-----------------

Type: Windows Defender Antivirus

Type:

Type: Windows Firewall

Graphics
--------

Features
Compositing: WebRender
Asynchronous Pan/Zoom: wheel input enabled; scrollbar drag enabled; keyboard enabled; autoscroll enabled
WebGL 1 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000beec) EGL_VERSION: 1.4 (ANGLE 2.1.0.8df54289d717) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_ANDROID_blob_cache EGL_ANDROID_recordable EGL_ANGLE_image_d3d11_texture EGL_ANGLE_create_context_backwards_compatible EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_KHR_debug EGL_ANGLE_explicit_context EGL_ANGLE_feature_control
WebGL 1 Driver Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 1070 Ti Direct3D11 vs_5_0 ps_5_0)
WebGL 1 Driver Version: OpenGL ES 2.0.0 (ANGLE 2.1.0.8df54289d717)
WebGL 1 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_memory_size GL_ANGLE_multi_draw GL_ANGLE_multiview_multisample GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_provoking_vertex GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_lose_context GL_CHROMIUM_sync_query GL_EXT_blend_func_extended GL_EXT_blend_minmax GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_float_blend GL_EXT_frag_depth GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_bptc GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_parallel_shader_compile GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_depth24 GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_3D GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object OES_compressed_EAC_R11_signed_texture OES_compressed_EAC_R11_unsigned_texture OES_compressed_EAC_RG11_signed_texture OES_compressed_EAC_RG11_unsigned_texture OES_compressed_ETC2_RGB8_texture OES_compressed_ETC2_RGBA8_texture OES_compressed_ETC2_punchthroughA_RGBA8_texture OES_compressed_ETC2_punchthroughA_sRGB8_alpha_texture OES_compressed_ETC2_sRGB8_alpha8_texture OES_compressed_ETC2_sRGB8_texture
WebGL 1 Extensions: ANGLE_instanced_arrays EXT_blend_minmax EXT_color_buffer_half_float EXT_float_blend EXT_frag_depth EXT_shader_texture_lod EXT_sRGB EXT_texture_compression_bptc EXT_texture_filter_anisotropic MOZ_debug OES_element_index_uint OES_standard_derivatives OES_texture_float OES_texture_float_linear OES_texture_half_float OES_texture_half_float_linear OES_vertex_array_object WEBGL_color_buffer_float WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_depth_texture WEBGL_draw_buffers WEBGL_lose_context
WebGL 2 Driver WSI Info: EGL_VENDOR: Google Inc. (adapter LUID: 000000000000beec) EGL_VERSION: 1.4 (ANGLE 2.1.0.8df54289d717) EGL_EXTENSIONS: EGL_EXT_create_context_robustness EGL_ANGLE_d3d_share_handle_client_buffer EGL_ANGLE_d3d_texture_client_buffer EGL_ANGLE_surface_d3d_texture_2d_share_handle EGL_ANGLE_query_surface_pointer EGL_ANGLE_window_fixed_size EGL_ANGLE_keyed_mutex EGL_ANGLE_surface_orientation EGL_ANGLE_direct_composition EGL_NV_post_sub_buffer EGL_KHR_create_context EGL_EXT_device_query EGL_KHR_image EGL_KHR_image_base EGL_KHR_gl_texture_2D_image EGL_KHR_gl_texture_cubemap_image EGL_KHR_gl_renderbuffer_image EGL_KHR_get_all_proc_addresses EGL_KHR_stream EGL_KHR_stream_consumer_gltexture EGL_NV_stream_consumer_gltexture_yuv EGL_ANGLE_flexible_surface_compatibility EGL_ANGLE_stream_producer_d3d_texture EGL_ANGLE_create_context_webgl_compatibility EGL_CHROMIUM_create_context_bind_generates_resource EGL_CHROMIUM_sync_control EGL_EXT_pixel_format_float EGL_KHR_surfaceless_context EGL_ANGLE_display_texture_share_group EGL_ANGLE_create_context_client_arrays EGL_ANGLE_program_cache_control EGL_ANGLE_robust_resource_initialization EGL_ANGLE_create_context_extensions_enabled EGL_ANDROID_blob_cache EGL_ANDROID_recordable EGL_ANGLE_image_d3d11_texture EGL_ANGLE_create_context_backwards_compatible EGL_EXTENSIONS(nullptr): EGL_EXT_client_extensions EGL_EXT_platform_base EGL_EXT_platform_device EGL_ANGLE_platform_angle EGL_ANGLE_platform_angle_d3d EGL_ANGLE_device_creation EGL_ANGLE_device_creation_d3d11 EGL_ANGLE_experimental_present_path EGL_KHR_client_get_all_proc_addresses EGL_KHR_debug EGL_ANGLE_explicit_context EGL_ANGLE_feature_control
WebGL 2 Driver Renderer: Google Inc. -- ANGLE (NVIDIA GeForce GTX 1070 Ti Direct3D11 vs_5_0 ps_5_0)
WebGL 2 Driver Version: OpenGL ES 3.0.0 (ANGLE 2.1.0.8df54289d717)
WebGL 2 Driver Extensions: GL_ANGLE_client_arrays GL_ANGLE_copy_texture_3d GL_ANGLE_depth_texture GL_ANGLE_explicit_context GL_ANGLE_explicit_context_gles1 GL_ANGLE_framebuffer_blit GL_ANGLE_framebuffer_multisample GL_ANGLE_instanced_arrays GL_ANGLE_lossy_etc_decode GL_ANGLE_memory_size GL_ANGLE_multi_draw GL_ANGLE_multiview_multisample GL_ANGLE_pack_reverse_row_order GL_ANGLE_program_cache_control GL_ANGLE_provoking_vertex GL_ANGLE_request_extension GL_ANGLE_robust_client_memory GL_ANGLE_texture_compression_dxt3 GL_ANGLE_texture_compression_dxt5 GL_ANGLE_texture_multisample GL_ANGLE_texture_usage GL_ANGLE_translated_shader_source GL_CHROMIUM_bind_generates_resource GL_CHROMIUM_bind_uniform_location GL_CHROMIUM_color_buffer_float_rgb GL_CHROMIUM_color_buffer_float_rgba GL_CHROMIUM_copy_compressed_texture GL_CHROMIUM_copy_texture GL_CHROMIUM_lose_context GL_CHROMIUM_sync_query GL_EXT_blend_func_extended GL_EXT_blend_minmax GL_EXT_color_buffer_float GL_EXT_color_buffer_half_float GL_EXT_debug_marker GL_EXT_discard_framebuffer GL_EXT_disjoint_timer_query GL_EXT_draw_buffers GL_EXT_float_blend GL_EXT_frag_depth GL_EXT_instanced_arrays GL_EXT_map_buffer_range GL_EXT_occlusion_query_boolean GL_EXT_read_format_bgra GL_EXT_robustness GL_EXT_sRGB GL_EXT_shader_texture_lod GL_EXT_texture_compression_bptc GL_EXT_texture_compression_dxt1 GL_EXT_texture_compression_s3tc_srgb GL_EXT_texture_filter_anisotropic GL_EXT_texture_format_BGRA8888 GL_EXT_texture_norm16 GL_EXT_texture_rg GL_EXT_texture_storage GL_EXT_unpack_subimage GL_KHR_debug GL_KHR_parallel_shader_compile GL_KHR_robust_buffer_access_behavior GL_NV_EGL_stream_consumer_external GL_NV_fence GL_NV_pack_subimage GL_NV_pixel_buffer_object GL_OES_EGL_image GL_OES_EGL_image_external GL_OES_EGL_image_external_essl3 GL_OES_depth24 GL_OES_depth32 GL_OES_element_index_uint GL_OES_get_program_binary GL_OES_mapbuffer GL_OES_packed_depth_stencil GL_OES_rgb8_rgba8 GL_OES_standard_derivatives GL_OES_surfaceless_context GL_OES_texture_3D GL_OES_texture_border_clamp GL_OES_texture_float GL_OES_texture_float_linear GL_OES_texture_half_float GL_OES_texture_half_float_linear GL_OES_texture_npot GL_OES_vertex_array_object GL_OVR_multiview GL_OVR_multiview2 OES_compressed_EAC_R11_signed_texture OES_compressed_EAC_R11_unsigned_texture OES_compressed_EAC_RG11_signed_texture OES_compressed_EAC_RG11_unsigned_texture OES_compressed_ETC2_RGB8_texture OES_compressed_ETC2_RGBA8_texture OES_compressed_ETC2_punchthroughA_RGBA8_texture OES_compressed_ETC2_punchthroughA_sRGB8_alpha_texture OES_compressed_ETC2_sRGB8_alpha8_texture OES_compressed_ETC2_sRGB8_texture
WebGL 2 Extensions: EXT_color_buffer_float EXT_float_blend EXT_texture_compression_bptc EXT_texture_filter_anisotropic MOZ_debug OES_texture_float_linear OVR_multiview2 WEBGL_compressed_texture_s3tc WEBGL_compressed_texture_s3tc_srgb WEBGL_debug_renderer_info WEBGL_debug_shaders WEBGL_lose_context
Direct2D: true
Uses Tiling (Content): true
Off Main Thread Painting Enabled: true
Off Main Thread Painting Worker Count: 4
Target Frame Rate: 240
DirectWrite: true (10.0.18362.476)
GPU #1
Active: Yes
Description: NVIDIA GeForce GTX 1070 Ti
Vendor ID: 0x10de
Device ID: 0x1b82
Driver Version: 26.21.14.3200
Driver Date: 7-24-2019
Drivers: C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumdx.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumdx.dll C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumd.dll,C:\WINDOWS\System32\DriverStore\FileRepository\nv_dispi.inf_amd64_db678424d2641c3d\nvldumd.dll
Subsys ID: 00000000
RAM: 8192
GPU #2
Active: No
RAM: 0
Diagnostics
AzureCanvasBackend: direct2d 1.1
AzureCanvasBackend (UI Process): skia
AzureContentBackend: skia
AzureContentBackend (UI Process): skia
AzureFallbackCanvasBackend (UI Process): none
CMSOutputProfile: 10528 bytes, too large
Display0: 1920x1080@60Hz
Display1: 1920x1080@240Hz
DisplayCount: 2
GPUProcessPid: 21416
GPUProcess: Terminate GPU Process
Device Reset: Trigger Device Reset
ClearType Parameters: \\.\DISPLAY1 [ Gamma: 1.8 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50 ] \\.\DISPLAY2 [ Gamma: 1.8 Pixel Structure: RGB ClearType Level: 100 Enhanced Contrast: 50 ]
Decision Log
WEBRENDER:
opt-in by default: WebRender is an opt-in feature
available by user: Qualified enabled by pref
WEBRENDER_PARTIAL:
available by user: Enabled
WEBRENDER_ANGLE:
opt-in by default: WebRender ANGLE is an opt-in feature
available by user: Enabled
WEBRENDER_DCOMP_PRESENT:
opt-in by default: WebRender DirectComposition is an opt-in feature
available by user: Enabled
ADVANCED_LAYERS:
blocked by env: Blocked from fallback candidate by WebRender usage
WEBGPU:
disabled by default: Disabled by default




Media
-----

Audio Backend: wasapi
Max Channels: 2
Preferred Sample Rate: 48000
Output Devices
Name: Group
DELL U2414H (NVIDIA High Definition Audio):
Realtek HD Audio 2nd output (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Digital Audio (HDMI) (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
NVIDIA Output (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Speakers (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
DELL AW2518HF (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Speakers (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
DELL AW2518HF (NVIDIA High Definition Audio):
Digital Audio (S/PDIF) (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
DELL U2414H (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
DELL AW2518HF (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Internal AUX Jack (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Headphones (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
DELL U2414H (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Digital Audio (HDMI) (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
:
Realtek Digital Output (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Internal AUX Jack (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
NVIDIA Output (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Input Devices
Name: Group
Subwoofer (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Rear Pink In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Internal AUX Jack (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Internal AUX Jack (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Front Pink In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Internal AUX Jack (NVIDIA High Definition Audio): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Front Green In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Line In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Rear (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Microphone (FaceCam VGA): USB\VID_0458&PID_7089&MI_02\7&27552904&0&0002
Rear Blue In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Desktop Microphone (Microsoft® LifeCam HD-3000): USB\VID_045E&PID_0779&MI_02\7&20cb7350&0&0002
Microphone (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Microphone (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Stereo Mix (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Desktop Microphone (2- Microsoft® LifeCam HD-3000): USB\VID_045E&PID_0779&MI_02\7&338523f5&0&0002
Microphone (2- FaceCam VGA): USB\VID_0458&PID_7089&MI_02\7&3a0ed9a9&0&0002
Rear Orange In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Side (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Internal AUX Jack (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10DE&DEV_0083&SUBSYS_1462C303&REV_1001\5&1c18572d&2&0001
Microphone (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Front (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Rear Black In (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Line In (High Definition Audio Device): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Center (Realtek(R) Audio): HDAUDIO\FUNC_01&VEN_10EC&DEV_1220&SUBSYS_1458A0C3&REV_1001\5&2d267199&0&0001
Media Capabilities
Enumerate database

Important Modified Preferences
------------------------------

browser.cache.disk.filesystem_reported: 1
browser.contentblocking.category: standard
browser.search.region: RO
browser.startup.homepage_override.buildID: 20200510092917
browser.startup.homepage_override.mstone: 78.0a1
browser.urlbar.placeholderName: Google
dom.forms.autocomplete.formautofill: true
dom.push.userAgentID: 3db90fd01aa2438185ca92583ddf47cf
extensions.lastAppVersion: 78.0a1
gfx.crash-guard.status.wmfvpxvideo: 2
gfx.crash-guard.wmfvpxvideo.appVersion: 78.0a1
gfx.crash-guard.wmfvpxvideo.deviceID: 0x1b82
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dom.ipc.processCount.webIsolated: 1

Places Database
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JavaScript
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Accessibility
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NSPR
Expected minimum version: 4.25
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NSS
Expected minimum version: 3.52
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NSSSMIME
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NSSSSL
Expected minimum version: 3.52
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NSSUTIL
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Sandbox
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The regression range is surprising because the map tiles don't appear to use blob images (unless there is a blob mask involved which doesn't show up with the flashing pref).
In renderdoc I can see that the tiles are drawn on a grey background and the blue part is rendered with 1px gaps between the map tiles, letting a grey line show through. Then some more stuff is rendered on top of it but it doesn't matter.

The gap between the tiles is really a gap between the quads that renders these tiles and not a masking artifact as shown by renderdoc highlighting the draw call in the second screenshot I posted. So it looks like something snapping related.

It is easier to reproduce this with a scaling factor applied (I had layout.css.devPixelsPerPx set to 1.4).

Gnome X11, GTX1060, Debian Testing
mozregression --find-fix --bad 2020-05-11 --good 2020-07-06 --pref gfx.webrender.all:true layout.css.devPixelsPerPx:1.4 -a https://www.windy.com/

15:24.11 INFO: First good revision: da69b8391ceb0f7bd95ae543b98a41d39eab6881
15:24.11 INFO: Last bad revision: bbcbf5721a9e02e43f093a4c8458759574dc12e6
15:24.11 INFO: Pushlog:
https://hg.mozilla.org/integration/autoland/pushloghtml?fromchange=bbcbf5721a9e02e43f093a4c8458759574dc12e6&tochange=da69b8391ceb0f7bd95ae543b98a41d39eab6881

da69b8391ceb0f7bd95ae543b98a41d39eab6881 Andrew Osmond — Bug 1628657 - Make canvas use computed reference frame transforms. r=kvark