Added trace events to ResourceDispatcher to try capturing uncategorized time. This is part of an effort to identify what contributes to the ~12.6% "uncategorized" time from the android top 25k experiment.

Since we'll be re-running the experiment with tracing in the future, would like to have tracing events that cover the costlier things that DevTools timeline covers (ResourceReceivedData and ResourceReceiveResponse), as well as some other calls which accounted for ~1% of traces for sites high in "uncategorized" time.

BUG=

Review URL: https://codereview.chromium.org/26940003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229596 0039d316-1c4b-4281-b951-d872f2087c98
Add trace events for WebMediaPlayerImpl frame painting.

Adding trace events to help visualize how long frames are waiting
to be painted, when frames are dropped, and how long repaint requests
are pending.

BUG=291731

Review URL: https://codereview.chromium.org/26967006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@229597 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 229596
SVN changes up to revision 229597