Fixup SVGSVGElement.createSVGTransformFromMatrix IDL definition

The optional SVGMatrix with a default of undefined is nonsensical, and
is not in line with the spec (where the argument is not optional).

Remove the 'optional' qualifier and the default value. This aligns
behavior with Gecko. (The exception thrown now is about arity, and not
about type mismatch as previously.)

As a result, the move of the [StrictTypeChecking] attribute to the
interface can be completed.

Review URL: https://codereview.chromium.org/149603007

git-svn-id: svn://svn.chromium.org/blink/trunk@167014 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Revert of Web Animations: Defer timing updates (https://codereview.chromium.org/159403002/)

Reason for revert:
Broke three browser_tests:

http://build.chromium.org/p/chromium.webkit/builders/Linux%20Tests%20%28dbg%29/builds/1634

CreateConfirmationText
NewProfileDefaultsFocus
ShowCreateConfirmationOnSuccess

They hit an assert:

ASSERTION FAILED: m_compositableValues
../../third_party/WebKit/Source/core/animation/Animation.h(58) : const CompositableValueList* WebCore::Animation::compositableValues() const

Original issue's description:
> This patch defers timing updates from the Web Animations API to
> animation frames. Updating timing will now request an animation
> frame and update the timing information on that frame. We store
> bits on the Timelines and Players to indicate whether they need
> updates.
> 
> The timing information on a TimedItem is updated upon access if
> its Player needs an update. The bit on Timeline is used to make
> sure getComputedStyle returns up-to-date information.
> 
> BUG=334926
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=166977

TBR=dstockwell@chromium.org,timloh@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=334926

Review URL: https://codereview.chromium.org/146213007

git-svn-id: svn://svn.chromium.org/blink/trunk@167016 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Devirtualize isStretchingChildren

There is no need for this to be virtual if we know the RenderObject is a RenderDeprecatedFlexibleBox, which we do here.
Also clean the method up a bit.

Review URL: https://codereview.chromium.org/154343002

git-svn-id: svn://svn.chromium.org/blink/trunk@167017 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: Remove global dependencies on WebInspector.debuggerModel. BreakpointsSidebarPane

BUG=

Review URL: https://codereview.chromium.org/138913018

git-svn-id: svn://svn.chromium.org/blink/trunk@167018 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Don't use task modes for non-debugger tasks

BUG=301514
R=kinuko@chromium.org,tyoshino@chromium.org

Review URL: https://codereview.chromium.org/159843005

git-svn-id: svn://svn.chromium.org/blink/trunk@167019 bbb929c8-8fbe-4397-9dbb-9b2b20218538