Merge PatternSkia into Pattern

This patch merges PatternSkia.cpp into Pattern now that the platform
graphics abstraction is no longer necessary. This is primarily a
code move with the following exceptions:
1) platformDestroy() was removed. The associated code now exists
   in the Pattern destructor.
2) setPlatformPatternSpaceTransform() was removed. The associated
   code now exists in Pattern::setPatternSpaceTransform.
3) platformPattern has been renamed "shader" and the unused
   transform parameter has been removed. The one callsite in
   PlatformContextSkia has been updated to reflect this change.

BUG=

Review URL: https://codereview.chromium.org/14145004

git-svn-id: svn://svn.chromium.org/blink/trunk@148385 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix issue with comparing signed and unsigned for Android FFT.

Make kMaxFFTPow2Size be unsigned.

BUG=

Review URL: https://codereview.chromium.org/14262012

git-svn-id: svn://svn.chromium.org/blink/trunk@148386 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Merge TransformationMatrixSkia into TransformationMatrix and AffineTransform

This patch removes TransformationMatrixSkia now that the platform graphics
abstraction is no longer necessary. This is a pure code move.

BUG=

Review URL: https://codereview.chromium.org/14239003

git-svn-id: svn://svn.chromium.org/blink/trunk@148387 bbb929c8-8fbe-4397-9dbb-9b2b20218538