Enable the volume slider in Ash for windows.

BUG=227247

Review URL: https://codereview.chromium.org/178883004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255215 0039d316-1c4b-4281-b951-d872f2087c98
TaskManager: Remove some unused/unnecessary methods.

What's removed:
 - The idea of unique_id's (these were for the now-gone webUI taskmanager).
 - The GetResourceExtension() method, which the tests no longer need.
 - The IsBackground getter, which is not used.

BUG=348836

Review URL: https://codereview.chromium.org/186153002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255217 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255217
Fix FileManagerFileTasksComplexTest.FindFileHandlerTasks test failing

Test is failing because FileManagerFileTasksComplexTest.FindFileHandlerTasks
doesn't initialize URL system request context. But URL fetch was started due
to misprint.

BUG=343589
TEST=unit_tests
NOTRY=true

Review URL: https://codereview.chromium.org/187603009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255218 0039d316-1c4b-4281-b951-d872f2087c98
Attempt to exclude flaky content_browsertests on Linux tsan bot

BUG=349634
TBR=phoglund@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/180183009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@255219 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 255219