trimmed stable release 31.0.1650.63
Merge remote-tracking branch 'origin/feature/bbEnhancements/30.0.1599.101' into feature/bbEnhancements/31.0.1650.63

Conflicts:
	chromium/src/third_party/WebKit/Source/core/core.gypi
	chromium/src/third_party/WebKit/Source/core/page/DOMWindow.h
	chromium/src/third_party/WebKit/Source/core/page/DragController.cpp
Fix compile errors for v31

* Frame::editor() now returns reference instead of pointer
  (https://chromiumcodereview.appspot.com/23518002)
* Range::ownerDocument() now returns reference instead of pointer
  (https://chromiumcodereview.appspot.com/23467007)
* Node::document() now returns reference instead of pointer
  (https://codereview.chromium.org/23819007)
* v8::HandleScope now requires an isolate
  (https://chromiumcodereview.appspot.com/23788005)
* Also, use toIsolate() to get the isolate from the frame, instead of using
  context->GetIsolate()
* Also, make fireBbContextMenuEvent a free static function since it doesn't
  need to be exposed in the header
* isImageBlocked in WebContextMenuData has been removed in favor of
  hasImageContents (https://codereview.chromium.org/22938006,
  https://chromiumcodereview.appspot.com/23037018)