Move StyleSheetContents completely into garbage collected heap.

All [Pass]RefPtr's replaced with transition types and it is now RefCountedWillBeGarbageCollectedFinalized.

BUG=341815

Review URL: https://codereview.chromium.org/172363003

git-svn-id: svn://svn.chromium.org/blink/trunk@167474 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Removed O(n!) traversal of selectors for selectorList.

When collectFeaturesFromSelector got a for-loop for tagHistory in [1], the
for-loop for tagHistory was kept in collectFeaturesFromSelectorList which
means we did n! visits of n sub-selectors in selectors like
:-webkit-any(.a.b.c).

[1] https://codereview.chromium.org/143653010

R=esprehn,chrishtr
BUG=335247

Review URL: https://codereview.chromium.org/172993002

git-svn-id: svn://svn.chromium.org/blink/trunk@167475 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add option to disable navigation on drag drop

BUG=342394

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=166940

Review URL: https://codereview.chromium.org/147493016

git-svn-id: svn://svn.chromium.org/blink/trunk@167476 bbb929c8-8fbe-4397-9dbb-9b2b20218538