Seen on Socorro. The latest crash of this signature affects WebRender in some way. (Btw, there are a lot other crash signatures with "drop_in_place" _from the last week_ that do not have a bug. I couldn't find WebRender in others so far: https://crash-stats.mozilla.com/search/?signature=~drop_in_place&date=%3E%3D2017-12-06T22%3A30%3A00.000Z&date=%3C2017-12-13T22%3A30%3A00.000Z&_sort=-date&_facets=signature&_columns=date&_columns=signature&_columns=product&_columns=version&_columns=build_id&_columns=platform#facet-signature ) bp-60d7db3c-4629-42f9-a2dc-776650171208 20171207220423 Win10 > 0 mozglue.dll arena_dalloc memory/build/mozjemalloc.cpp:3488 > 1 mozglue.dll HeapFree memory/mozalloc/winheap.cpp:64 > 2 xul.dll core::ptr::drop_in_place<webrender::internal_types::RenderedDocument> src/libcore/ptr.rs:59 > 3 xul.dll webrender_bindings::bindings::wr_renderer_update gfx/webrender_bindings/src/bindings.rs:501 > 4 xul.dll mozilla::wr::RenderThread::UpdateAndRender(mozilla::wr::WrWindowId) gfx/webrender_bindings/RenderThread.cpp:223 > 5 xul.dll mozilla::wr::RenderThread::NewFrameReady(mozilla::wr::WrWindowId) gfx/webrender_bindings/RenderThread.cpp:174 > 6 xul.dll mozilla::detail::RunnableMethodImpl<mozilla::dom::HTMLMediaElement::ChannelLoader*, void ( mozilla::dom::HTMLMediaElement::ChannelLoader::*)(mozilla::dom::HTMLMediaElement*), 1, 0, mozilla::dom::HTMLMediaElement*>::Run() xpcom/threads/nsThreadUtils.h:1192 > 7 xul.dll MessageLoop::DoWork() ipc/chromium/src/base/message_loop.cc:535 > 8 xul.dll base::MessagePumpDefault::Run(base::MessagePump::Delegate*) ipc/chromium/src/base/message_pump_default.cc:36 > 9 xul.dll MessageLoop::RunHandler() ipc/chromium/src/base/message_loop.cc:319 > 10 xul.dll MessageLoop::Run() ipc/chromium/src/base/message_loop.cc:299 > 11 xul.dll base::Thread::ThreadMain() ipc/chromium/src/base/thread.cc:181 > 12 xul.dll `anonymous namespace'::ThreadFunc ipc/chromium/src/base/platform_thread_win.cc:28 > 13 kernel32.dll BaseThreadInitThunk > 14 ntdll.dll RtlUserThreadStart History (wr = contains webrender): wr bp-60d7db3c-4629-42f9-a2dc-776650171208 2017-12-08 16:37:01 59.0a1 20171207220423 Win10 -- bp-7d792859-6249-4c88-89a6-43bd00171202 2017-12-02 12:33:00 59.0a1 20171130220131 Win10 -- bp-69a1df30-96f0-4573-b82c-532fe0171124 2017-11-24 08:07:14 59.0a1 20171123100420 Win8.1 -- bp-9f2aabe7-a4a5-4cb1-ae45-db58b0171119 2017-11-19 21:08:33 59.0a1 20171119100329 Win8.1 -- bp-ea028f31-f2f1-42b4-ba73-4c0030171117 2017-11-17 19:18:00 59.0a1 20171114100042 Win10 -- bp-a969bcaf-79d5-4e1f-9072-729810171112 2017-11-12 01:12:15 58.0a1 20171111100349 Win7

Maybe this is just a duplicate of core::ptr::drop_in_place<T>: bug 1424451 or bug 1385925 (not authorized) (?)

I don't see anything WebRender-related from the last three months.