Make BrowsingDataHandler observe WebHistoryService deletions

Make BrowsingDataHandler observe WebHistoryService deletions

BrowsingDataHandler observes local history deletions, but not synced
history deletions. In cases where there are no local history entries
to delete, it can happen that the history page does not reload and it
looks as if the deletion failed.

See https://docs.google.com/document/d/1Fd6CdBf6UMbYbkwSjEKyFOxew0Xid5IaT-QwnFchjig/
for background.

This CL
1. Adds an Observer subclass to the WebHistoryService.
2. Registers BrowsingHistoryHandler as a WebHistoryService::Observer;
   and since WebHistoryService's existence is based on whether history
   sync is enabled, we also register as a SyncServiceObserver.
3. Adds a test to browsing_history_handler_unittest.cc.

Also tested manually on Android - seems to solve the problem described
in the above mentioned document.

TBR=tsergeant@chromium.org,lshang@chromium.org,sky@chromium.org,dbeam@chromium.org
BUG=604114, 630164
Review-Url: https://codereview.chromium.org/2263613002
Cr-Commit-Position: refs/heads/master@{#414679}
(cherry picked from commit d39070b1ac01776e5a3800a9ef55fe43dce74225)

Committed: https://chromium.googlesource.com/chromium/src/+/8ce19cc272209840e306fde7485e5bc6f34432bb

[msramek, 2016-09-01 09:12:57]

Description was changed from

==========
Make BrowsingDataHandler observe WebHistoryService deletions

BrowsingDataHandler observes local history deletions, but not synced
history deletions. In cases where there are no local history entries
to delete, it can happen that the history page does not reload and it
looks as if the deletion failed.

See
https://docs.google.com/document/d/1Fd6CdBf6UMbYbkwSjEKyFOxew0Xid5IaT-QwnFchjig/
for background.

This CL
1. Adds an Observer subclass to the WebHistoryService.
2. Registers BrowsingHistoryHandler as a WebHistoryService::Observer;
   and since WebHistoryService's existence is based on whether history
   sync is enabled, we also register as a SyncServiceObserver.
3. Adds a test to browsing_history_handler_unittest.cc.

Also tested manually on Android - seems to solve the problem described
in the above mentioned document.

TBR=tsergeant@chromium.org,lshang@chromium.org,sky@chromium.org,dbeam@chromiu...
BUG=604114,630164

Review-Url: https://codereview.chromium.org/2263613002
Cr-Commit-Position: refs/heads/master@{#414679}
(cherry picked from commit d39070b1ac01776e5a3800a9ef55fe43dce74225)
==========

to

==========
Make BrowsingDataHandler observe WebHistoryService deletions

BrowsingDataHandler observes local history deletions, but not synced
history deletions. In cases where there are no local history entries
to delete, it can happen that the history page does not reload and it
looks as if the deletion failed.

See
https://docs.google.com/document/d/1Fd6CdBf6UMbYbkwSjEKyFOxew0Xid5IaT-QwnFchjig/
for background.

This CL
1. Adds an Observer subclass to the WebHistoryService.
2. Registers BrowsingHistoryHandler as a WebHistoryService::Observer;
   and since WebHistoryService's existence is based on whether history
   sync is enabled, we also register as a SyncServiceObserver.
3. Adds a test to browsing_history_handler_unittest.cc.

Also tested manually on Android - seems to solve the problem described
in the above mentioned document.

TBR=tsergeant@chromium.org,lshang@chromium.org,sky@chromium.org,dbeam@chromiu...
BUG=604114,630164

Review-Url: https://codereview.chromium.org/2263613002
Cr-Commit-Position: refs/heads/master@{#414679}
(cherry picked from commit d39070b1ac01776e5a3800a9ef55fe43dce74225)

Committed:
https://chromium.googlesource.com/chromium/src/+/8ce19cc272209840e306fde7485e...
==========

[msramek, 2016-09-01 09:13:04]

Committed patchset #1 (id:1) manually as
8ce19cc272209840e306fde7485e5bc6f34432bb.

[msramek, 2016-09-01 09:15:14]

Reviewers of the old CL (https://codereview.chromium.org/2263613002) FYI: I have
merged this back to M54.