Oilpan: Remove RefCounted from DOMWindow in the Oilpan build.

Noticed in passing that DOMWindow was still RefCountedGarbageCollected.
It doesn't have to be.

R=haraken@chromium.org, oilpan-reviews@chromium.org

Review URL: https://codereview.chromium.org/335183003

git-svn-id: svn://svn.chromium.org/blink/trunk@176594 bbb929c8-8fbe-4397-9dbb-9b2b20218538
CompositingInputsUpdater should compute scrollParent

Instead of walking up the tree to find the scroll parent 
for every RenderLayer when computing the compositing
requirements, we now compute it while walking down the tree
for only the RenderLayers with dirty compositing state.

Note: This CL is a minor tweak of abarth's patch
(https://codereview.chromium.org/340303004). It adds a
small walk to ensure that there is no stacking context
between the layer and the scroller.

BUG=None

Review URL: https://codereview.chromium.org/344023002

git-svn-id: svn://svn.chromium.org/blink/trunk@176595 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mediastream: Use const references for the string arguments in RTCStatsResponse.

BUG=

Review URL: https://codereview.chromium.org/348803002

git-svn-id: svn://svn.chromium.org/blink/trunk@176596 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Roll Closure compiler to 8b4b812b275ea3bf5cf296a2df94dede03609120

Most prominent changes:
  - Multiple externs improvements
  - Promises support
  - Improved type inference
  - ES6 support (to a certain degree)
  - Custom coding conventions enforcement
  - Improved parser API (used by JSDocValidator)

This patch also incorporates:
  - Updated JSDocValidator (due to the new Closure parser API);
  - JS modifications (due to the updated Closure externs).

R=aandrey@chromium.org, sergeyv@chromium.org, vsevik@chromium.org, aandrey, sergeyv, vsevik

Review URL: https://codereview.chromium.org/339353002

git-svn-id: svn://svn.chromium.org/blink/trunk@176597 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move list of hidden record types into TimelineUIUtils

Drive-by: changed type enum used in TracingTimelineModel.js to the one describing tracing events.

BUG=361045
R=loislo@chromium.org

Review URL: https://codereview.chromium.org/348003002

git-svn-id: svn://svn.chromium.org/blink/trunk@176598 bbb929c8-8fbe-4397-9dbb-9b2b20218538