Ignore tabs with duplicate IDs when merging tab models on cold start

Ignore tabs with duplicate IDs when merging tab models on cold start

If a merge is in progress and the Activity gets killed, there could
be two tab metadata files that contain some duplicate tab IDs.
When merging these two metadata files on application cold start,
ignore tabs with duplicate ids.

BUG=602498
Committed: https://crrev.com/3a26c14f818c56ed46a426584fc3230ad72c52c7
Cr-Commit-Position: refs/heads/master@{#406992}

[Theresa, 2016-07-20 22:50:09]

The CQ bit was checked by twellington@chromium.org to run a CQ dry run

[commit-bot: I haz the power, 2016-07-20 22:50:36]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Theresa, 2016-07-20 22:53:08]

The CQ bit was checked by twellington@chromium.org to run a CQ dry run

[Theresa, 2016-07-20 22:53:28]

twellington@chromium.org changed reviewers:
+ dfalcantara@chromium.org

[commit-bot: I haz the power, 2016-07-20 22:53:28]

Dry run: CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[Theresa, 2016-07-20 22:53:29]

ptal

[commit-bot: I haz the power, 2016-07-20 23:41:19]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-20 23:41:19]

Dry run: This issue passed the CQ dry run.

[gone, 2016-07-21 20:53:41]

lgtm

Wrapping my head around the twisty codepaths is taking a lot of effort... For my
future reference: TabPersistentStore#loadState() can trigger both loading the
current ChromeTabbedActivity's tabs and merging of the other
ChromeTabbedActivity's tabs at the same time.  However, calling
TabPersistentStore#mergeState() (which is triggered when one
ChromeTabbedActivity is resumed and and the other one is minimized or dead)
prevents the merge from occuring if there is already a load in progress. 
Assuming that's correct, is there a comment in TabPersistentStore about that
somewhere?

https://chromiumcodereview.appspot.com/2166123002/diff/20001/chrome/android/j...
File
chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/TabPersistentStoreTest.java
(right):

https://chromiumcodereview.appspot.com/2166123002/diff/20001/chrome/android/j...
chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/TabPersistentStoreTest.java:581:
// Write the same data to tab_state0 and tab_state1.
newline before // comment?

[Theresa, 2016-07-21 21:45:44]

Added some code comments to loadState() and mergeState() and
mMergeInProgress/mLoadInProgress

https://chromiumcodereview.appspot.com/2166123002/diff/20001/chrome/android/j...
File
chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/TabPersistentStoreTest.java
(right):

https://chromiumcodereview.appspot.com/2166123002/diff/20001/chrome/android/j...
chrome/android/javatests/src/org/chromium/chrome/browser/tabmodel/TabPersistentStoreTest.java:581:
// Write the same data to tab_state0 and tab_state1.
On 2016/07/21 20:53:40, dfalcantara wrote:
> newline before // comment?

Done.

[Theresa, 2016-07-21 21:45:48]

The CQ bit was checked by twellington@chromium.org

[Theresa, 2016-07-21 21:45:48]

The patchset sent to the CQ was uploaded after l-g-t-m from
dfalcantara@chromium.org
Link to the patchset: https://chromiumcodereview.appspot.com/2166123002/#ps60001
(title: "Add comments")

[commit-bot: I haz the power, 2016-07-21 21:46:20]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-21 21:50:22]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-07-21 21:50:23]

Try jobs failed on following builders:
  android_arm64_dbg_recipe on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_arm6...)
  android_clang_dbg_recipe on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_clan...)
  android_compile_dbg on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/android_comp...)
  cast_shell_android on master.tryserver.chromium.android (JOB_FAILED,
https://build.chromium.org/p/tryserver.chromium.android/builders/cast_shell_a...)
  ios-device on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-device/builds...)
  ios-simulator on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios-simulator/bui...)
  mac_chromium_compile_dbg_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)
  mac_chromium_rel_ng on master.tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_rel_...)

[Theresa, 2016-07-21 22:20:10]

The CQ bit was checked by twellington@chromium.org to run a CQ dry run

[Theresa, 2016-07-21 22:20:28]

The CQ bit was checked by twellington@chromium.org

[Theresa, 2016-07-21 22:20:29]

The patchset sent to the CQ was uploaded after l-g-t-m from
dfalcantara@chromium.org
Link to the patchset: https://codereview.chromium.org/2166123002/#ps80001
(title: "Rebase")

[commit-bot: I haz the power, 2016-07-21 22:20:40]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-07-21 23:38:57]

Committed patchset #5 (id:80001)

[commit-bot: I haz the power, 2016-07-21 23:40:12]

Description was changed from

==========
Ignore tabs with duplicate IDs when merging tab models on cold start

If a merge is in progress and the Activity gets killed, there could
be two tab metadata files that contain some duplicate tab IDs.
When merging these two metadata files on application cold start,
ignore tabs with duplicate ids.

BUG=602498
==========

to

==========
Ignore tabs with duplicate IDs when merging tab models on cold start

If a merge is in progress and the Activity gets killed, there could
be two tab metadata files that contain some duplicate tab IDs.
When merging these two metadata files on application cold start,
ignore tabs with duplicate ids.

BUG=602498

Committed: https://crrev.com/3a26c14f818c56ed46a426584fc3230ad72c52c7
Cr-Commit-Position: refs/heads/master@{#406992}
==========

[commit-bot: I haz the power, 2016-07-21 23:40:13]

Patchset 5 (id:??) landed as
https://crrev.com/3a26c14f818c56ed46a426584fc3230ad72c52c7
Cr-Commit-Position: refs/heads/master@{#406992}