Support for providing media stream audio track to speech recognition - Blink implementation.

[ WebKit CL ]
  Renderer CL    : http://crrev.com/499233003
  Browser CL     : http://crrev.com/549373003

Introduces |webkitSpeechRecognition.audioTrack| attribute. Set to null by default.

When the attribute is set to null, SR is done by default implementation
(getting audio from the audio input device on the browser).

When the attribute is set to a MediaStreamTrack it should get audio data 
from that track after |start()|. The track is utilized once |start()| is called.

For unsupported tracks (e.g. from a file rather than a microphone)
the chromium implementation should bubble up the error once |start()| is called.

Changing of the attribute after |start()| is called should have no effect 
on the running session. This is the same behavioral pattern as for the other attributes.

Design doc: http://goo.gl/9Ot3PC

Intent to implement: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/G2lRTzZXmW4

BUG=408940

Review URL: https://codereview.chromium.org/448163003

git-svn-id: svn://svn.chromium.org/blink/trunk@182851 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Enable TextBlob rendering for gradient & pattern paints.

We had disabled the TextBlob code path when using gradients or patterns
due to a Skia side shader space issue. That should be fixed and we can
now use text blobs for paints with shaders also.

R=jbroman@chromium.org,eae@chromium.org

Review URL: https://codereview.chromium.org/609533002

git-svn-id: svn://svn.chromium.org/blink/trunk@182852 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove unused and undefined RenderImage::highQualityRepaintTimerFired

Not be confused with the one in ImageQualityController.

BUG=

Review URL: https://codereview.chromium.org/609293003

git-svn-id: svn://svn.chromium.org/blink/trunk@182854 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move paint code for RenderScrollbar and RenderScrollbarPart into ScrollbarPainter.

In so doing, exposed a new getPart() method on RenderScrollbar to get the part.
Also, this patch changes the code in RenderScrollbarPart to explicitly call the BlockPainter::paint method, rather than relying on virtual function calls. This is possible because RenderScrollbarPart is a FINAL class that inherits from BlockPainter. Therefore all of these calls must be the BlockPainter version.

BUG=412088

Review URL: https://codereview.chromium.org/613503002

git-svn-id: svn://svn.chromium.org/blink/trunk@182855 bbb929c8-8fbe-4397-9dbb-9b2b20218538