Added User Timing UMA metrics to the histograms definition

Metrics themselves were added here:
https://chromiumcodereview.appspot.com/23245004

BUG=262567

Review URL: https://codereview.chromium.org/74943008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238269 0039d316-1c4b-4281-b951-d872f2087c98
[Telemetry] Refactoring in preparation for video-based Speed Index support.

1. Introduce a platform API for video capture.
2. Implement that API for KitKat+ releases of Android.
3. Refactor speed index metric to have Paint Rect and Video impls. Use video
   when available.

BUG=323813

Review URL: https://codereview.chromium.org/93733002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238270 0039d316-1c4b-4281-b951-d872f2087c98
cc: Support animating scroll offset

This makes cc::LayerAnimationController support animating scroll offset.
This is needed for implementing the CSSOM View smooth scroll API.

BUG=243871

Review URL: https://codereview.chromium.org/95763002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238271 0039d316-1c4b-4281-b951-d872f2087c98
Enhance check_ecs_deps to allow locally built libraries.

Added a verbose option so the rationality of the above can be checked.

BUG=None
TEST=local, and on non-static build.

Review URL: https://codereview.chromium.org/95903002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238272 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238272