Oilpan: Fix isAlive dispatching for GarbageCollectedMixins.

Update the test so that adjustment is needed and use a weak hash set
of mixin pointers.

I realized this didn't work when I needed to use it for the
Node hierarchy.

R=erik.corry@gmail.com, kouhei@chromium.org, oilpan-reviews@chromium.org, vegorov@chromium.org

Review URL: https://codereview.chromium.org/222653003

git-svn-id: svn://svn.chromium.org/blink/trunk@170688 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add a missing null check to LinkStyle::process()

This is a speculative fix for crashes that are reported from wild.

BUG=358844
R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/220723012

git-svn-id: svn://svn.chromium.org/blink/trunk@170689 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations: Introduce String based KeyframeEffectModel

Note: This is a rework of issue 212023004

This patch refactors KeyframeEffectModel to support different types of
keyframe values. The common keyframe logic is retained in
KeyframeEffectModelBase to be inherited by the keyframe type specialisations.

KeyframeEffectModel is then templated on Keyframe type, with a hierarchy of Keyframes
including StringKeyframe and AnimatableValueKeyframe being introduced.

String based keyframes are being introduced to properly support the JS API
for Web Animations element.animate().

Review URL: https://codereview.chromium.org/215883005

git-svn-id: svn://svn.chromium.org/blink/trunk@170690 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Mark various tests NeedsManualRebaseline in advance of v8 return parsing change

TBR=rossberg
BUG=359194

Review URL: https://codereview.chromium.org/222773003

git-svn-id: svn://svn.chromium.org/blink/trunk@170692 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix crash in isDocumentDoneLoading()

Document::loader() might be null if re-entrancy is involved.

BUG=357570

Review URL: https://codereview.chromium.org/222433003

git-svn-id: svn://svn.chromium.org/blink/trunk@170693 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove dead code from RenderBox:sizesLogicalWidthToFitContent()

Review URL: https://codereview.chromium.org/219333009

git-svn-id: svn://svn.chromium.org/blink/trunk@170695 bbb929c8-8fbe-4397-9dbb-9b2b20218538