Drop RenderObject::hasBlendMode

Remove RenderObject::hasBlendMode in favor of RenderStyle::hasBlendMode.
Also remove the gating on the RuntimeEnabledFeatures feature in
RenderStyle, since this should be handled by the CSS parser already.
Gating also removed for the 'isolation' property.

Review URL: https://codereview.chromium.org/746163002

git-svn-id: svn://svn.chromium.org/blink/trunk@185823 bbb929c8-8fbe-4397-9dbb-9b2b20218538
10 files changed