Remove duplicated provideMediaKeysTo() in MediaKeysClient.h

Though MediaKeysController has already provideMediaKeysTo() which is being used by WebViewImpl, MediaKeysClient.h also has provideMediaKeysTo() unnecessary.

BUG=none

Review URL: https://codereview.chromium.org/338713002

git-svn-id: svn://svn.chromium.org/blink/trunk@177184 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove WTF_USE_SYSTEM_MALLOC

We never use the system malloc anymore.

Review URL: https://codereview.chromium.org/345203007

git-svn-id: svn://svn.chromium.org/blink/trunk@177185 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations API: Add layout tests for element.animate() keyframes

Adds layout tests for keyframes with the following configurations:
 - 3 keyframes with and without offsets
 - Keyframes offsets specified out of order
 - Explicit null offset value
 - Shared offset keyframes with overlapping/disjoint properties
 - Invalid keyframe offsets
 - Per keyframe easing

Fixes flaky test issues due to bug 367903 by running the tests
inside requestAnimationFrame().

BUG=367644

Review URL: https://codereview.chromium.org/253963002

git-svn-id: svn://svn.chromium.org/blink/trunk@177186 bbb929c8-8fbe-4397-9dbb-9b2b20218538