Support CanvasPattern.setTransform

Patterns have a transformation matrix, which controls how the pattern is used when it is painted. 

Initially, a pattern's transformation matrix must be the identity transform. 

When the setTransform() method is invoked on the pattern, the user agent must replace the pattern's
transformation matrix with the one described by the SVGMatrix object provided as an argument to the method.

Specification: http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#dom-canvaspattern-settransform
IDL Definition: http://www.whatwg.org/specs/web-apps/current-work/multipage/scripting.html#2dcontext:dom-canvaspattern-settransform
Intent to Implement: https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/dUt2_2xn3NU

BUG=289572
R=junov@chromium.org

Review URL: https://codereview.chromium.org/527193002

git-svn-id: svn://svn.chromium.org/blink/trunk@181737 bbb929c8-8fbe-4397-9dbb-9b2b20218538
In generated dictionary toImpl(), throw all exceptions via ExceptionState

This allows us to simplify callers by not having a v8::TryCatch there, and
instead only check the ExceptionState object.

Review URL: https://codereview.chromium.org/556273003

git-svn-id: svn://svn.chromium.org/blink/trunk@181738 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: extract TracingManager from TracingModel

Let TracingManager handle back-end interactions while TracingModel
acts just as a container for trace events. The model will later be
moved out of sdk and this will allow introducing backing storage for
trace events (e.g. a file).

BUG=412709

Review URL: https://codereview.chromium.org/557013005

git-svn-id: svn://svn.chromium.org/blink/trunk@181741 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Factor painting code out of RenderBox into a new class called BoxPainter.

Along the way, create BoxDecorationData and BorderEdge classes, to represent classes
that used to be internal to the RenderBox and subclass implementations. Also moves
a couple of methods to RenderStyle that use only style data.

This CL increases the size of RenderBox, RenderTable, Render TableCell and RenderFieldset objects by one pointer,
to accomodate a back pointer from the BoxPainter to the Render object.

BUG=412088

Review URL: https://codereview.chromium.org/550363004

git-svn-id: svn://svn.chromium.org/blink/trunk@181742 bbb929c8-8fbe-4397-9dbb-9b2b20218538