Switch Blink to using new Skia SkCanvas::drawPicture method

As of Skia 9b14f26d (Alter SkCanvas::drawPicture (devirtualize, take const SkPicture, take pointer) - https://codereview.chromium.org/313613004) SkCanvas::drawPicture has an alternate signature. The old entry point is deprecated.

Note: this patch cannot be landed until the corresponding Skia change is rolled into Chromium & Blink.

Review URL: https://codereview.chromium.org/316863003

git-svn-id: svn://svn.chromium.org/blink/trunk@175569 bbb929c8-8fbe-4397-9dbb-9b2b20218538