Move TestRunner from CppVariable to gin::Wrappable

BUG=297480, 331301
TEST=all layout tests

Review URL: https://codereview.chromium.org/185263006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257079 0039d316-1c4b-4281-b951-d872f2087c98
Fix a crash when tracing is enabled.

InitStartupTracing posts a task to end the startup tracing so it
should only be called after the main message loop is started
(PostMainMessageLoopStart()). Otherwise the browser will crash
when MessagePumpForUI::ScheduleWork() is called before
MessagePumpForUI::Start().

BUG=352223

Review URL: https://codereview.chromium.org/198713003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257080 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 257080
Add different error codes for getUserMedia.
The spec now says that the error name is UA specific so I have now
Implemented a few different ones.
This patch is depending on a Blink Patch.

BUG=132812

Review URL: https://codereview.chromium.org/180633008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@257081 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 257081