Steps To Reproduce: 1. Start Firefox 2. Enter Customize Actual Results: No transition animation. Expected Results: Add Customize tab and shrink toolbar/content area should be animated

Hey Alice, I am unable to reproduce this bug on Nightly on my Windows 7 box. Are you able to reproduce on a clean profile? -Mike

(In reply to Mike Conley (:mconley) from comment #1) > Hey Alice, > > I am unable to reproduce this bug on Nightly on my Windows 7 box. Are you > able to reproduce on a clean profile? > > -Mike Yes.

Can you please capture a screencast from the point of opening the browser? Thanks!

Screen capture Please observe it carefully. Compare 1st(00:25) and 2nd(00:33)

Thanks Alice - I think I need still more information: 1) Has this behaviour been consistent for a while, or is there a regression range you can point me at? 2) Have you ever used the Gecko Profiler before? Would you be comfortable gathering and posting a profile for me from your machine? Thanks, -Mike

(In reply to Mike Conley (:mconley) from comment #5) > Thanks Alice - I think I need still more information: > > 1) Has this behaviour been consistent for a while, or is there a regression > range you can point me at? > 2) Have you ever used the Gecko Profiler before? Would you be comfortable > gathering and posting a profile for me from your machine? > > Thanks, > > -Mike I think this is not a regression. I think element(which is initialized lazily) fails animation. Similar Bug 893016, Bug 893016 I like no animation anyway. Fixing this bug is not worth.

(In reply to Alice0775 White from comment #6) > (In reply to Mike Conley (:mconley) from comment #5) > > Thanks Alice - I think I need still more information: > > > > 1) Has this behaviour been consistent for a while, or is there a regression > > range you can point me at? > > 2) Have you ever used the Gecko Profiler before? Would you be comfortable > > gathering and posting a profile for me from your machine? > > > > Thanks, > > > > -Mike > > I think this is not a regression. > I think element(which is initialized lazily) fails animation. > Similar Bug 893016, Bug 893016 > Hm, ok, interesting. Would you mind providing for me the Graphics section from your about:support, along with: 1) What operating system you're currently using - you're in classic mode, so it must be either Win 7 or XP. 2) What system font size is set 3) The general specs on your machine (processor, RAM) > I like no animation anyway. Fixing this bug is not worth. Fair enough - but I still would like to figure this out if possible.

Graphics -------- Adapter Description: ATI Radeon HD 4300/4500 Series Adapter Drivers: aticfx64 aticfx64 aticfx32 aticfx32 atiumd64 atidxx64 atiumdag atidxx32 atiumdva atiumd6a atitmm64 Adapter RAM: 512 ClearType Parameters: Gamma: 2200 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 50 Device ID: 0x954f Direct2D Enabled: true DirectWrite Enabled: true (6.1.7601.18245) Driver Date: 4-29-2013 Driver Version: 8.970.100.1100 GPU #2 Active: false GPU Accelerated Windows: 1/1 Direct3D 10 Vendor ID: 0x1002 WebGL Renderer: Google Inc. -- ANGLE (ATI Radeon HD 4300/4500 Series Direct3D9Ex vs_3_0 ps_3_0) windowLayerManagerRemote: false AzureCanvasBackend: direct2d AzureContentBackend: direct2d AzureFallbackCanvasBackend: cairo AzureSkiaAccelerated: 0 Windows7 SP1 HomePremium 64bit Classic Visual Style 100% default Core2Quad@2.5GHz, 8GB This problem also happens on Ubuntu12.04 32bit, GNOME Classic