Only call updateReflectionInfo in RenderLayer::styleChanged when reflection did change

It doesn't seem we had any early outs for reflections which is nasty. It
looks like once you added a reflection we'd keep mallocing up new transforms
inside RenderLayerReflectionInfo::updateAfterStyleChange on every style
recalc even if the reflection didn't change.

This patch fixes that and adds asserts.

BUG=335703

Review URL: https://codereview.chromium.org/139093008

git-svn-id: svn://svn.chromium.org/blink/trunk@166003 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rename CSSSegmentedFontFaceCache to FontFaceCache.

This class uses FontFace objects as key, so "FontFaceCache" describes it better.

BUG=

Review URL: https://codereview.chromium.org/148813003

git-svn-id: svn://svn.chromium.org/blink/trunk@166004 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add blink_gc_plugin variable to enable the clang plugin for checking GC consistency.

R=abarth@chromium.org, ager@chromium.org
BUG=

Review URL: https://codereview.chromium.org/133473002

git-svn-id: svn://svn.chromium.org/blink/trunk@166005 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Implement InstallEvent for ServiceWorker

Most methods are left unimplemented yet.

Also add plumbing to dispatch InstallEvent from chromium
(via ServiceWorkerGlobalScopeProxy).

InstallEvent (and InstallPhaseEvent) is defined in:
https://github.com/slightlyoff/ServiceWorker/blob/master/service_worker.ts#L109

BUG=285976
TEST=to be added in chromium, tested manually locally

Review URL: https://codereview.chromium.org/144943002

git-svn-id: svn://svn.chromium.org/blink/trunk@166006 bbb929c8-8fbe-4397-9dbb-9b2b20218538