Make the distiller cancellable.

Makes the distiller cancellable, it is now safe to delete the distiller
even when distillation is in progress. On deleting the distiller any
callbacks posted by ongoing tasks are now cancelled.

BUG=340431
TEST=Included.

Review URL: https://codereview.chromium.org/189543005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256463 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256463
Files.app: Stop to use updateIndexes method.

Change events published by updateIndexes discard cached items in the file list, and it may break the browser tests.
This CL temporary stops to use updateIndexes and takes the previous implementation backs.

TBR=yoshiki
BUG=none
TEST=browser_tests

Review URL: https://codereview.chromium.org/196143006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256464 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256464
Enable WebRtcBrowserTests.CanSetupAudioAndVideoCallWithoutMsidAndBundle.

I can not repeat flakiness. Both code and test has been changed since this was disabled on Win. Neither test or code is platform dependent.

BUG=235089
R=phoglund@chromium.org, tommi@chromium.org

Review URL: https://codereview.chromium.org/189913015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256465 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256465