Chrommium Bisect:
https://chromium.googlesource.com/chromium/src/+log/d5e03bd4b4424f1647291784f166773035f69046..20e2e36f0d46869b499d208e52a9de6c66c17b27?pretty=fuller&n=10000

Suspect: https://chromium.googlesource.com/chromium/src/+/5ad4e08d15110e8212fae941d4638e2e4df7e4c1

@sunnyps: Could you please check whether this is caused with respect to your change, if not please help us in assigning it to the right owner.

Note: Issue is not seen on Mac(10.13.1,10.13.6,10.14.2) and Linux(14.04 LTS) OS.

The above CL is likely responsible.  It was also merged to M72 to fix  issue 904322  which is a less critical bug IMO.  I'll be back on 1/15 and M72 stable cut is on 1/22 so unless someone else can investigate this maybe we should revert this on M72?

sunnyps: I'll try to confirm locally and if it's not a trivia fix, I'll revert on trunk and on M72. No worries. Enjoy your vacation.

Interestingly, I can't reproduce this issue on three Windows machines.

1) Lenovo laptop with Intel KabyLake
2) MS Surface Pro with Intel KabyLake
3) Desktop with NVIDIA

All three are on Windows 10. I tested with current Canary, which is 73.0.3661, which is newer than yours.

Please provide your about:gpu and chrome://version/?show-variations-cmd contents

It *might* have something to do with either true Aero "glass" (see attached
screenshot which seems to be from Windows 7) or with custom titlebar
disabled (--disable-features=Windows10CustomTitlebar).

I run Canary with --disable-features=Windows10CustomTitlebar and made sure it's disabled, and I can't reproduce this bug.

We don't have a Win7 in house in both GPU team or QA team, so we can't test Aero mode.

Just to update:

With respect to comment 6:

Issue is not seen on win-10 after disabling "-disable-features=Windows10CustomTitlebar" and it is still reproducible on Win-7 machine using canary build #73.0.3665.0.

Kindly check attached video for the same.

Thank you.

Deleted: Actual_Issue.mp4 373 KB

	Actual_Issue.mp4 373 KB View Download

Please provide the about:gpu info on the machines you can reproduce this, because I can't reproduce the issue on the three machines I testes (all three are win 10)

Also, I build a Chrome mini installer, which excludes the above mentioned suspected CL:

https://drive.google.com/drive/folders/1W3Pi1wVzbtrQs36i7ZS_F3pJitj9_JJ_?usp=sharing

Can you download the mini_installer.exe and install chromium on machines you can reproduce this issue? Please confirm if reverting the above mentioned CL does or does not fix the issue.

Ping! We will need some feedback from original reporter who can reproduce this issue to take the next action!

dipteeb@ thanks for filing the issue.

Please follow up and provide necessary action immediately.

@zmo and @ligimole: I apologize for the delay in updating the issue.

Below is the update:

With respect to comment 9:

Issue is not seen on Windows-10 machine after disabling "-disable-features=Windows10CustomTitlebar" but it is reproducible on Windows (7,8,8.1) machine.

Please refer About:gpu info for Win-7 machine.

Kindly refer attached screenshot for the same.

Thank You.

Deleted: Actual_Issue.mp4 418 KB

	Actual_Issue.mp4 418 KB View Download

Deleted: GPU_Info.png 640 KB

	GPU_Info.png 640 KB View Download

dipteeb@ see comment # 10, please check by installing the build.

#10
Hello, I am experiencing the issue on a Windows 7 machine too.

I've installed the custom build you uploaded, and the flickering does not occur anymore.

With respected to comment 10:

Downloaded above mentioned mini installer and installed it on my machine (i.e.win-7) and above issue is seem fixed.

Please refer attached screen cast for the same.

Thank you.

Deleted: Fix_Issue.mp4 445 KB

	Fix_Issue.mp4 445 KB View Download

OK, thanks for confirming. Let me revert the CL then.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/99f5438aba0fb5e137221ee18f6c6969f4654d0e

commit 99f5438aba0fb5e137221ee18f6c6969f4654d0e
Author: Zhenyao Mo <zmo@chromium.org>
Date: Fri Jan 11 21:50:56 2019

Revert "Fix app window titlebar blending with direct composition"

This reverts commit 5ad4e08d15110e8212fae941d4638e2e4df7e4c1.

Reason for revert:  crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
>
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
>
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
>
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#618684}

TBR=sky@chromium.org,sunnyps@chromium.org,bsep@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug:  904322 , 918461 
Change-Id: I681f37f264884cdfab7425eadfbd6c26bbf2d953
Reviewed-on: https://chromium-review.googlesource.com/c/1407602
Commit-Queue: Zhenyao Mo <zmo@chromium.org>
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622168}
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.h
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.h
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/ui/views/win/hwnd_message_handler.cc
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/ui/views/win/hwnd_message_handler.h
[modify] https://crrev.com/99f5438aba0fb5e137221ee18f6c6969f4654d0e/ui/views/win/hwnd_message_handler_delegate.h

The following revision refers to this bug: 
https://chromium.googlesource.com/chromium/src.git/+/507aaf39e1ef42cb9389832582f11fe14f4104ee

Commit: 507aaf39e1ef42cb9389832582f11fe14f4104ee
Author: zmo@chromium.org
Commiter: zmo@chromium.org
Date: 2019-01-11 22:00:25 +0000 UTC

Revert "Fix app window titlebar blending with direct composition"

This reverts commit 2dd99ab580747edaea6fb0c1ad46526059e900c4.

Reason for revert:  crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
> 
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
> 
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
> 
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Original-Commit-Position: refs/heads/master@{#618684}(cherry picked from commit 5ad4e08d15110e8212fae941d4638e2e4df7e4c1)
> Reviewed-on: https://chromium-review.googlesource.com/c/1391319
> Reviewed-by: Zhenyao Mo <zmo@chromium.org>
> Cr-Commit-Position: refs/branch-heads/3626@{#521}
> Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}

TBR=zmo@chromium.org,sunnyps@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug:  904322 , 918461 
Change-Id: If2281410ba24efa0850d7c4116a10adc1473cf5f
Reviewed-on: https://chromium-review.googlesource.com/c/1407657
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#652}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}

Reverted the offending CL on the ToT and M72.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/507aaf39e1ef42cb9389832582f11fe14f4104ee

commit 507aaf39e1ef42cb9389832582f11fe14f4104ee
Author: Zhenyao Mo <zmo@chromium.org>
Date: Fri Jan 11 22:00:25 2019

Revert "Fix app window titlebar blending with direct composition"

This reverts commit 2dd99ab580747edaea6fb0c1ad46526059e900c4.

Reason for revert:  crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
> 
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
> 
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
> 
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Original-Commit-Position: refs/heads/master@{#618684}(cherry picked from commit 5ad4e08d15110e8212fae941d4638e2e4df7e4c1)
> Reviewed-on: https://chromium-review.googlesource.com/c/1391319
> Reviewed-by: Zhenyao Mo <zmo@chromium.org>
> Cr-Commit-Position: refs/branch-heads/3626@{#521}
> Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}

TBR=zmo@chromium.org,sunnyps@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug:  904322 , 918461 
Change-Id: If2281410ba24efa0850d7c4116a10adc1473cf5f
Reviewed-on: https://chromium-review.googlesource.com/c/1407657
Reviewed-by: Zhenyao Mo <zmo@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#652}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.h
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.h
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/ui/views/win/hwnd_message_handler.cc
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/ui/views/win/hwnd_message_handler.h
[modify] https://crrev.com/507aaf39e1ef42cb9389832582f11fe14f4104ee/ui/views/win/hwnd_message_handler_delegate.h

Reopening to investigate this further

I was able to repro on a Win 7 Lenovo Thinkpad with Intel HD 4600 with a release build (is_debug = false, is_component_build = false, dcheck_always_on = false, is_official_build = true).  I couldn't repro with dcheck enabled non-optimized component build so it's likely due to a race somewhere.

The above CL changed the logic slightly in two places:

1) The DWM frame size is updated after the frame contents are invalidated instead of before.  See the discussion here: https://chromium-review.googlesource.com/c/chromium/src/+/1382928/6/ui/views/win/hwnd_message_handler.cc#3122
2) We clear the frame region on every WM_ERASEBKGND instead of the first one.

I'm going to investigate if any of these changes is the root cause.

Looks like it's because of clear on every WM_ERASEBKGND.  I'm curious about why we get WM_ERASEBKGND when we switch tabs but not curious enough :)

For now, I'm relanding the CL with the clear on the first WM_ERASEBKGND after frame type changes which matches the previous logic.

CL with fix: https://chromium-review.googlesource.com/c/chromium/src/+/1410388

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/55e596a4337e58480882e56d5fd31627eb1dd668

commit 55e596a4337e58480882e56d5fd31627eb1dd668
Author: Sunny Sachanandani <sunnyps@chromium.org>
Date: Tue Jan 15 23:57:46 2019

Reland "Fix app window titlebar blending with direct composition"

This is a reland of 5ad4e08d15110e8212fae941d4638e2e4df7e4c1

The only change is that we clear the DWM frame on the first
WM_ERASEBKGND message after frame type changes instead of doing it for
every message.  This fixes  https://crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
>
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
>
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
>
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#618684}

Bug:  904322 ,  918461 
Change-Id: I032ff424d204cb20d724f6be26b3e6fc8d5d0ec0
Reviewed-on: https://chromium-review.googlesource.com/c/1410388
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622883}
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/win/hwnd_message_handler.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/win/hwnd_message_handler.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/win/hwnd_message_handler_delegate.h

dipteeb@ can you please verify that the issue is fixed for you after next canary version which should contain the above CL?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/55e596a4337e58480882e56d5fd31627eb1dd668

commit 55e596a4337e58480882e56d5fd31627eb1dd668
Author: Sunny Sachanandani <sunnyps@chromium.org>
Date: Tue Jan 15 23:57:46 2019

Reland "Fix app window titlebar blending with direct composition"

This is a reland of 5ad4e08d15110e8212fae941d4638e2e4df7e4c1

The only change is that we clear the DWM frame on the first
WM_ERASEBKGND message after frame type changes instead of doing it for
every message.  This fixes  https://crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
>
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
>
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
>
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#618684}

Bug:  904322 ,  918461 
Change-Id: I032ff424d204cb20d724f6be26b3e6fc8d5d0ec0
Reviewed-on: https://chromium-review.googlesource.com/c/1410388
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622883}
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/win/hwnd_message_handler.cc
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/win/hwnd_message_handler.h
[modify] https://crrev.com/55e596a4337e58480882e56d5fd31627eb1dd668/ui/views/win/hwnd_message_handler_delegate.h

Just to update:

Above issue is fixed on latest Beta build #72.0.3626.64 and Latest canary build #73.0.3673.0 using win(7,8.1,8) OS.

Kindly refer attached screencast.

Thank you.

Deleted: Fix_Canary.mp4 298 KB

	Fix_Canary.mp4 298 KB View Download

Deleted: Fix_Beta.mp4 297 KB

	Fix_Beta.mp4 297 KB View Download

Thanks!

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170

commit fe5f6cceb5028adf1b1cb3e9a586ec7de4741170
Author: Sunny Sachanandani <sunnyps@chromium.org>
Date: Fri Jan 18 21:42:52 2019

[merge to m72] Reland "Fix app window titlebar blending with direct composition"

This is a reland of 5ad4e08d15110e8212fae941d4638e2e4df7e4c1

The only change is that we clear the DWM frame on the first
WM_ERASEBKGND message after frame type changes instead of doing it for
every message.  This fixes  https://crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
>
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
>
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
>
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#618684}

Bug:  904322 ,  918461 
Change-Id: I032ff424d204cb20d724f6be26b3e6fc8d5d0ec0
Reviewed-on: https://chromium-review.googlesource.com/c/1410388
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#622883}(cherry picked from commit 55e596a4337e58480882e56d5fd31627eb1dd668)
Reviewed-on: https://chromium-review.googlesource.com/c/1423113
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#736}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.cc
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/chrome/browser/ui/views/apps/app_window_desktop_window_tree_host_win.h
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.cc
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/chrome/browser/ui/views/frame/browser_desktop_window_tree_host_win.h
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/ui/views/widget/desktop_aura/desktop_window_tree_host_win.cc
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/ui/views/widget/desktop_aura/desktop_window_tree_host_win.h
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/ui/views/win/hwnd_message_handler.cc
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/ui/views/win/hwnd_message_handler.h
[modify] https://crrev.com/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170/ui/views/win/hwnd_message_handler_delegate.h

The following revision refers to this bug: 
https://chromium.googlesource.com/chromium/src.git/+/fe5f6cceb5028adf1b1cb3e9a586ec7de4741170

Commit: fe5f6cceb5028adf1b1cb3e9a586ec7de4741170
Author: sunnyps@chromium.org
Commiter: sunnyps@chromium.org
Date: 2019-01-18 21:42:52 +0000 UTC

[merge to m72] Reland "Fix app window titlebar blending with direct composition"

This is a reland of 5ad4e08d15110e8212fae941d4638e2e4df7e4c1

The only change is that we clear the DWM frame on the first
WM_ERASEBKGND message after frame type changes instead of doing it for
every message.  This fixes  https://crbug.com/918461 

Original change's description:
> Fix app window titlebar blending with direct composition
>
> Clear the DWM frame area on WM_ERASEBKGND so that Chrome's client area
> blends with DWM frame for app windows.  Refactor the code to update and
> clear DWM frame and move it to hwnd message handler so that browser and
> app windows can share the same code.
>
> This mimics existing logic for updating the DWM frame and adds the clear
> DWM frame behavior to app windows, but one notable change is that it
> will clear on every WM_ERASEBKGND message, and not just the first one.
> This shouldn't have a performance impact and seems more correct anyway.
>
> Bug:  904322 
> Change-Id: I70c3ae97a94114dd63110736a35cef4dd887b1aa
> Reviewed-on: https://chromium-review.googlesource.com/c/1382928
> Reviewed-by: Scott Violet <sky@chromium.org>
> Reviewed-by: Bret Sepulveda <bsep@chromium.org>
> Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#618684}

Bug:  904322 ,  918461 
Change-Id: I032ff424d204cb20d724f6be26b3e6fc8d5d0ec0
Reviewed-on: https://chromium-review.googlesource.com/c/1410388
Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#622883}(cherry picked from commit 55e596a4337e58480882e56d5fd31627eb1dd668)
Reviewed-on: https://chromium-review.googlesource.com/c/1423113
Reviewed-by: Sunny Sachanandani <sunnyps@chromium.org>
Cr-Commit-Position: refs/branch-heads/3626@{#736}
Cr-Branched-From: d897fb137fbaaa9355c0c93124cc048824eb1e65-refs/heads/master@{#612437}