Note:
1) This issue is observed on all devices 
2)  Good Build: 57.0.2951.0
    Bad Build: 56.0.2952.0
3) Bisect range: https://chromium.googlesource.com/chromium/src/+log/56.0.2951.0..56.0.2952.0?pretty=fuller&n=10000
4)Bisect script is pointing to https://chromium.googlesource.com/chromium/src/+/ef5c846a3e5d3c994d962ddca7d40f4bc1476044
5) Please find logs and Video @ http://go/chrome-androidlogs1/6/681822

Sorry I couldn't find the "Clear form" option at Step 6.Did I miss something?
I tested on Samsung Galaxy Note 4 because I don't have a Note 5.

Deleted: screenshot.png 212 KB

	screenshot.png 212 KB View Download

@yabinh, Please find a video to reproduce the issue on Samsung Galaxy Note 4(SM-N10C)/KTU84P @ http://go/chrome-androidlogs1/6/681822-1.

OK. Now I'm able to repro it with aelias@'s help.
1. To show the "Clear form" option, go to "Settings->Autofill forms, and add an "Address" item;
2. To repro the bug, follow the original steps with Google keyboard instead of Samsung keyboard.

BTW, the bug can be also reproduced on other devices, like Nexus 5.

I'll keep looking into it.

Found the root cause.

Focusing in a form, auto filling it, and focusing out will call
1. setCompositionFromExistingText(“auto_filled_text”)
2. finishingComposingText()

At Step 2, we will delete the existing composition and insert new composition. Note that if the auto-filled text is modified, the “Clear form” will not clear it. So we shouldn't modify the text at Step 2.

Issue 686018 has been merged into this issue.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/81279cd5b209a34ca4f7702f2a10576faa50fdf9

commit 81279cd5b209a34ca4f7702f2a10576faa50fdf9
Author: aelias <aelias@chromium.org>
Date: Tue Feb 07 04:46:23 2017

Remove replaceComposition() calls in finishComposingText.

We recently split commitText("") into a new method finishComposingText, a no-op
commit that simply preserves the already existing composition.  But because
of its historical origins it still had the replaceComposition call in it.

This is causing a bug with "yellow" autofill status getting cleared due
to the operation being interpreted as user typing.  But also, it's unnecessary work
in general, and the input/compositionupdate events are just repeated from the last
setComposition() call.  So just clean them out and have a clear()/moveCaret() call.

As a result of this, I was also able to clean out another longstanding autofill
ignoring flag that no longer has anything to ignore.

TEST=WebViewTest.FinishComposingTextDoesntTriggerAutofillTextChange
BUG= 681822 

Review-Url: https://codereview.chromium.org/2664603002
Cr-Commit-Position: refs/heads/master@{#448546}

[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/components/autofill/content/renderer/autofill_agent.cc
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/components/autofill/content/renderer/autofill_agent.h
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/content/public/android/javatests/src/org/chromium/content/browser/input/ImeTest.java
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/LayoutTests/fast/events/composition-event-source-device-event-sender-expected.txt
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/LayoutTests/fast/events/ime-composition-events-001-expected.txt
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/Source/core/editing/InputMethodController.cpp
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/Source/web/WebFrameWidgetImpl.cpp
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/Source/web/WebViewImpl.cpp
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/Source/web/tests/WebViewTest.cpp
[modify] https://crrev.com/81279cd5b209a34ca4f7702f2a10576faa50fdf9/third_party/WebKit/public/web/WebAutofillClient.h

Your change meets the bar and is auto-approved for M57. Please go ahead and merge the CL to branch 2987 manually. Please contact milestone owner if you have questions.
Owners: amineer@(clank), cmasso@(bling), ketakid@(cros), govind@(desktop)

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b1b55fb2cf97a6274212b1f288ea20efff471901

commit b1b55fb2cf97a6274212b1f288ea20efff471901
Author: Alexandre Elias <aelias@chromium.org>
Date: Wed Feb 08 03:56:44 2017

Remove replaceComposition() calls in finishComposingText.

We recently split commitText("") into a new method finishComposingText, a no-op
commit that simply preserves the already existing composition.  But because
of its historical origins it still had the replaceComposition call in it.

This is causing a bug with "yellow" autofill status getting cleared due
to the operation being interpreted as user typing.  But also, it's unnecessary work
in general, and the input/compositionupdate events are just repeated from the last
setComposition() call.  So just clean them out and have a clear()/moveCaret() call.

As a result of this, I was also able to clean out another longstanding autofill
ignoring flag that no longer has anything to ignore.

TEST=WebViewTest.FinishComposingTextDoesntTriggerAutofillTextChange
BUG= 681822 

Review-Url: https://codereview.chromium.org/2664603002
Cr-Original-Commit-Position: refs/heads/master@{#448546}
Review-Url: https://codereview.chromium.org/2681023003 .
Cr-Commit-Position: refs/branch-heads/2987@{#381}
Cr-Branched-From: ad51088c0e8776e8dcd963dbe752c4035ba6dab6-refs/heads/master@{#444943}

[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/components/autofill/content/renderer/autofill_agent.cc
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/components/autofill/content/renderer/autofill_agent.h
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/content/public/android/javatests/src/org/chromium/content/browser/input/ImeTest.java
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/LayoutTests/fast/events/composition-event-source-device-event-sender-expected.txt
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/LayoutTests/fast/events/ime-composition-events-001-expected.txt
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/Source/core/editing/InputMethodController.cpp
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/Source/core/editing/InputMethodControllerTest.cpp
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/Source/web/WebFrameWidgetImpl.cpp
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/Source/web/WebViewImpl.cpp
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/Source/web/tests/WebViewTest.cpp
[modify] https://crrev.com/b1b55fb2cf97a6274212b1f288ea20efff471901/third_party/WebKit/public/web/WebAutofillClient.h

Verified with Chrome Beta release "57.0.2987.38" On Motox 2nd Gen.