[cr tool] Adding the Runner base class

BUG=316397

Review URL: https://codereview.chromium.org/99093002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238149 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238149
cc: add DevTools instrumentation for impl-side frames

This adds devtools_instrumentation::didBeginFrame() invoked from
Scheduler::BeginImplFrame() and
devtools_instrumentation::didCommitMainThreadFrame invoked from
LayerTreeHost::FinishCommitOnImplThread(). We use the latter to
associate impl-side frames with main thread ones on the DevTools
side.
Related blink-side patch: https://codereview.chromium.org/59793003/

BUG=305863

Review URL: https://codereview.chromium.org/60353002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238150 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238150