skip (gpu) canvas-toDataURL-webp until libwebp-0.4.1 lands

BUG=374343

Review URL: https://codereview.chromium.org/413403010

git-svn-id: svn://svn.chromium.org/blink/trunk@179090 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Introduce V8DOMConfiguration::InstanceOrPrototype enum

This is a simple refactoring.
We should use enum instead of '1 /* on prototype */' and '0 /* on instance */'.
There is no change in behavior.

Review URL: https://codereview.chromium.org/425853006

git-svn-id: svn://svn.chromium.org/blink/trunk@179091 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Cast highestEnclosingNodeOfType() return value to tighter type

Cast highestEnclosingNodeOfType() return value to tighter type to increase
code readability. This CL also renames the type checking functions passed
to highestEnclosingNodeOfType() to make it clear what type of Node/Element
is returned.

R=leviw@chromium.org

Review URL: https://codereview.chromium.org/417113011

git-svn-id: svn://svn.chromium.org/blink/trunk@179093 bbb929c8-8fbe-4397-9dbb-9b2b20218538