Revert of Revert of Elimate NOTIFICATION_GOOGLE_URL_UPDATED

Revert of Revert of Elimate NOTIFICATION_GOOGLE_URL_UPDATED (https://codereview.chromium.org/294563002/)

Reason for revert:
Things cycled green before this revert became active on the testers.

Original issue's description:
> Revert of Elimate NOTIFICATION_GOOGLE_URL_UPDATED (https://codereview.chromium.org/284343003/)
> 
> Reason for revert:
> speculative, browser_tests stated timing out on all non-dbg win main waterfall test bots, with a message such as
> 
> 
> E:\b\depot_tools\python276_bin\python_slave.exe E:\b\build\scripts\slave\runisolatedtest.py --test_name browser_tests --builder_name "Win7 Tests (1)" --checkout_dir E:\b\build\slave\Win7_Tests__1_\build E:\b\build\slave\Win7_Tests__1_\build\src\out\Release\browser_tests.exe -- E:\b\build\slave\Win7_Tests__1_\build\src\out\Release\browser_tests.exe --brave-new-test-launcher --test-launcher-bot-mode --test-launcher-total-shards=3 --test-launcher-shard-index=0 --lib=browser_tests --gtest_print_time --gtest_output=xml:E:\b\build\slave\Win7_Tests__1_\build\gtest-results\browser_tests\browser_tests.xml --test-launcher-summary-output=c:\users\chrome~2\appdata\local\temp\tmpfbmzn9
> 
> E:\b\depot_tools\python276_bin\python_slave.exe E:\b\build\slave\Win7_Tests__1_\build\src\tools\swarming_client\isolate.py run --isolated E:\b\build\slave\Win7_Tests__1_\build\src\out\Release\browser_tests.isolated -v -- --no-cr --test-launcher-bot-mode --test-launcher-total-shards=3 --test-launcher-shard-index=0 --gtest_output=xml:E:\b\build\slave\Win7_Tests__1_\build\gtest-results\browser_tests\browser_tests.xml --test-launcher-summary-output=c:\users\chrome~2\appdata\local\temp\tmpfbmzn9
>  INFO         isolate(685): CompleteState.load_isolate(E:\b\build\slave\Win7_Tests__1_\build, E:\b\build\slave\Win7_Tests__1_\build\src\chrome\browser_tests.isolate, {}, {}, {'EXECUTABLE_SUFFIX': '.exe'}, False)
>  INFO         isolate(156): normalize_path_variables(E:\b\build\slave\Win7_Tests__1_\build, {}, E:\b\build\slave\Win7_Tests__1_\build\src\chrome)
>  INFO  isolate_format( 57): determine_root_dir(E:\b\build\slave\Win7_Tests__1_\build\src\chrome, 80 files) -> E:\b\build\slave\Win7_Tests__1_\build\src
>  INFO         isolate( 84): recreate_tree(outdir=E:\b\build\slave\Win7_Tests__1_\isolate-2014-05-18gqemnl, indir=E:\b\build\slave\Win7_Tests__1_\build\src, files=9443, action=4, as_hash=False)
>  INFO         isolate(1266): Running ['E:\\b\\depot_tools\\python276_bin\\python_slave.exe', '../testing/test_env.py', u'..\\out\\Release/browser_tests.exe', '--test-launcher-bot-mode', '--no-cr', '--test-launcher-bot-mode', '--test-launcher-total-shards=3', '--test-launcher-shard-index=0', '--gtest_output=xml:E:\\b\\build\\slave\\Win7_Tests__1_\\build\\gtest-results\\browser_tests\\browser_tests.xml', '--test-launcher-summary-output=c:\\users\\chrome~2\\appdata\\local\\temp\\tmpfbmzn9'], cwd=E:\b\build\slave\Win7_Tests__1_\isolate-2014-05-18gqemnl\chrome
> 
> command timed out: 600 seconds without output, attempting to kill
> program finished with exit code 1
> 
> Original issue's description:
> > Elimate NOTIFICATION_GOOGLE_URL_UPDATED
> > 
> > This CL moves the remaining client of the NOTIFICATION_GOOGLE_URL_UPDATED
> > notification to instead register a callback with GoogleURLTracker and
> > eliminates the notification. It also migrate the GoogleURLTracker unittest from
> > listening for the notification to listening for the callback.
> > 
> > BUG=373261, 373237
> > TBR=thakis
> > 
> > Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271313
> 
> TBR=pkasting@chromium.org,blundell@chromium.org
> NOTREECHECKS=true
> NOTRY=true
> BUG=373261, 373237
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271320

TBR=pkasting@chromium.org,blundell@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=373261, 373237
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=271323

[Nico, 2014-05-19 01:17:04]

Created Revert of Revert of Elimate NOTIFICATION_GOOGLE_URL_UPDATED

[commit-bot: I haz the power, 2014-05-19 01:17:10]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/thakis@chromium.org/287233007/1

[commit-bot: I haz the power, 2014-05-19 01:17:52]

Change committed as 271323