WEBPImageDecoder: single line if's should prevail herein

We either consitently wrap single line if's in {}, or we
don't but how about we be consitent with the surrounding
code at least.

TBR=tkent@chromium.org
NOTRY=true

Review URL: https://chromiumcodereview.appspot.com/18270003

git-svn-id: svn://svn.chromium.org/blink/trunk@153610 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Service animations only as often as necessary.

Servicing of animations on the frame callback was added in r107575, however
that change failed to suspend the animation timer. As a result non-accelerated
animations were serviced by both the frame callback and animation timer
(at effectively 100hz), and accelerated animations were unnecessarily serviced
on the main thread (at 40hz) in addition to the compositor thread (also
resulting in extra commits being triggered in the compositor).

This change refactors the scheduling logic in AnimationController to request
a frame callback if animations must be serviced immediately, OR to use the
animation timer if servicing is required after a delay. When the page is
hidden, servicing is delayed until the page becomes visible and a frame
callback fires OR enough time has elapsed that an animation event must be
fired.

Source/core/page/animation/AnimationController.cpp:
  Centralize animation scheduling logic in scheduleService() and track
  time to next service and time to next event separately. Request a frame
  callback if service is required immediately otherwise use the animation
  timer.

R=jamesr@chromium.org
BUG=227161,123591

Review URL: https://chromiumcodereview.appspot.com/14048019

git-svn-id: svn://svn.chromium.org/blink/trunk@153611 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Implement the ::backdrop pseudo-element for modal <dialog>.

The Fullscreen spec defines ::backdrop, a pseudo-element rendered
immediately beneath top layer elements. This enables the grayed-out
screen effect, for example.

This commit implements ::backdrop for modal dialogs, which are the
currently the only residents of the top layer. The plan is for
fullscreen elements to also use the top layer, so they will use
::backdrop as well.

BUG=253909

Review URL: https://chromiumcodereview.appspot.com/17654008

git-svn-id: svn://svn.chromium.org/blink/trunk@153612 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Removed redundant comment.

TEST=none
BUG=none
R=haraken

Review URL: https://chromiumcodereview.appspot.com/18695005

git-svn-id: svn://svn.chromium.org/blink/trunk@153613 bbb929c8-8fbe-4397-9dbb-9b2b20218538