The first one is actually ChromeActivity leaking so applies to ChromeTabbedActivity as well.

Taking this one and adding labels to accelarate landing a fix to production.

BTW, this is how "dumpsys meminfo" reports number of objects:

1. First it calls Runtime.getRuntime().gc() to clear unreachable objects
2. Then it calls VMDebug.countInstancesOfClasses() to get actual counts

See https://cs.corp.google.com/aosp-master/frameworks/base/core/java/android/app/ActivityThread.java?rcl=f954f2d5cc2d254b2e4c1c4df33caf3bd66843b0&l=1043

Maybe we can do the same in a test?

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/810b810269e4329d50c089c26d77f47ea89b61ef

commit 810b810269e4329d50c089c26d77f47ea89b61ef
Author: yusufo <yusufo@chromium.org>
Date: Wed Apr 12 00:25:30 2017

Unregister from network changes on destroy in ContextualSearchTabHelper

This causes us to leak ChromeActivity instances and all the views
associated with them. In general we should always make sure to
unregister notifiers from application level singletons on destroy.

BUG= 710612 

Review-Url: https://codereview.chromium.org/2812143002
Cr-Commit-Position: refs/heads/master@{#463855}

[modify] https://crrev.com/810b810269e4329d50c089c26d77f47ea89b61ef/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchTabHelper.java

This bug requires manual review: We are only 12 days from stable.
Please contact the milestone owner if you have questions.
Owners: amineer@(Android), cmasso@(iOS), bhthompson@(ChromeOS), govind@(Desktop)

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

#3 fixed the leak, however the last closed CustomTabActivity still remains alive, referenced by:

→ root class org.chromium.chrome.browser.offlinepages.OfflinePageTabObserver.sInstance
→ org.chromium.chrome.browser.offlinepages.OfflinePageTabObserver@13109908.mContext
→ android.app.ContextImpl@13109928.mOuterContext
→ org.chromium.chrome.browser.customtabs.CustomTabActivity@13109a00

I think that one will keep moving from one activity to another. If you create another one, we wont have two activities. It leaves an extra activity even though we dont have any live.

That one was trickier to solve without changing the whole OfflineTabObserver idea which I feel like will have to go through the offline team.

This seemed like the quickest and most effective solution that can be cherrypicked

Merge approved for M58 branch 3029.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/615aaeab8b12051181cff795d1a1e7683f9a38ba

commit 615aaeab8b12051181cff795d1a1e7683f9a38ba
Author: Yusuf Ozuysal <yusufo@google.com>
Date: Wed Apr 12 21:26:06 2017

Unregister from network changes on destroy in ContextualSearchTabHelper

This causes us to leak ChromeActivity instances and all the views
associated with them. In general we should always make sure to
unregister notifiers from application level singletons on destroy.

BUG= 710612 

Review-Url: https://codereview.chromium.org/2812143002
Cr-Commit-Position: refs/heads/master@{#463855}
Committed: https://chromium.googlesource.com/chromium/src/+/810b810269e4329d50c089c26d77f47ea89b61ef

patch from issue 2812143002 at patchset 1 (http://crrev.com/2812143002#ps1)

Review-Url: https://codereview.chromium.org/2812373002 .
Cr-Commit-Position: refs/branch-heads/3029@{#681}
Cr-Branched-From: 939b32ee5ba05c396eef3fd992822fcca9a2e262-refs/heads/master@{#454471}

[modify] https://crrev.com/615aaeab8b12051181cff795d1a1e7683f9a38ba/chrome/android/java/src/org/chromium/chrome/browser/contextualsearch/ContextualSearchTabHelper.java

Updating the milestone and sending back to dskiba@ for adding related tests. I will also fork the offline related issue as a separate bug.

Figuring out how to add this check to tests is a tough one, because most of our tests are not black-box, and so the tests themselves end up holding onto references to the activities. 

This would be a great check to add if we were to write some espresso tests though.

Related: LeakCanary ( bug 505909 ). Where LeakCanary kind of fell apart for me was the no way to make it work for instrumentation tests.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21

commit d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21
Author: dskiba <dskiba@chromium.org>
Date: Mon May 08 18:36:27 2017

Add tests to make sure closed CCT activities are not leaked.

BUG=715724,  710612 

Review-Url: https://codereview.chromium.org/2847263003
Cr-Commit-Position: refs/heads/master@{#470057}

[modify] https://crrev.com/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21/base/android/java/src/org/chromium/base/ThreadUtils.java
[modify] https://crrev.com/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21/chrome/android/java/src/org/chromium/chrome/browser/toolbar/CustomTabToolbar.java
[modify] https://crrev.com/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21/chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarManager.java
[modify] https://crrev.com/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java
[modify] https://crrev.com/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTestBase.java
[modify] https://crrev.com/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21/chrome/test/android/javatests/src/org/chromium/chrome/test/util/ApplicationTestUtils.java

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/3f4a47063c35627779a3e4d7464e1398bcbf6467

commit 3f4a47063c35627779a3e4d7464e1398bcbf6467
Author: olka <olka@chromium.org>
Date: Tue May 09 12:53:52 2017

Revert of Add tests to make sure closed CCT activities are not leaked. (patchset #7 id:120001 of https://codereview.chromium.org/2847263003/ )

Reason for revert:
org.chromium.chrome.browser.customtabs.CustomTabActivityTest#testClosedBackActivitiesNotLeaked flaky on chromium.linux/Android Tests

See  Issue 719909 

Original issue's description:
> Add tests to make sure closed CCT activities are not leaked.
>
> BUG=715724,  710612 
>
> Review-Url: https://codereview.chromium.org/2847263003
> Cr-Commit-Position: refs/heads/master@{#470057}
> Committed: https://chromium.googlesource.com/chromium/src/+/d50d8466d0bdae0b5ae8af4108ecaa1376ed5f21

TBR=tedchoc@chromium.org,yusufo@chromium.org,torne@chromium.org,dskiba@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=715724,  710612 

Review-Url: https://codereview.chromium.org/2866213003
Cr-Commit-Position: refs/heads/master@{#470295}

[modify] https://crrev.com/3f4a47063c35627779a3e4d7464e1398bcbf6467/base/android/java/src/org/chromium/base/ThreadUtils.java
[modify] https://crrev.com/3f4a47063c35627779a3e4d7464e1398bcbf6467/chrome/android/java/src/org/chromium/chrome/browser/toolbar/CustomTabToolbar.java
[modify] https://crrev.com/3f4a47063c35627779a3e4d7464e1398bcbf6467/chrome/android/java/src/org/chromium/chrome/browser/toolbar/ToolbarManager.java
[modify] https://crrev.com/3f4a47063c35627779a3e4d7464e1398bcbf6467/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTest.java
[modify] https://crrev.com/3f4a47063c35627779a3e4d7464e1398bcbf6467/chrome/android/javatests/src/org/chromium/chrome/browser/customtabs/CustomTabActivityTestBase.java
[modify] https://crrev.com/3f4a47063c35627779a3e4d7464e1398bcbf6467/chrome/test/android/javatests/src/org/chromium/chrome/test/util/ApplicationTestUtils.java