Fix restrictions on squashing with incompatible scroll.

The previous logic could fail in some cases when the heuristic specified for the identity of the layer to squash
into did not match exactly the choice used later in assignLayersToBackings. The new code is a bit cleaner also.

BUG=261605

Review URL: https://codereview.chromium.org/195893026

git-svn-id: svn://svn.chromium.org/blink/trunk@169571 bbb929c8-8fbe-4397-9dbb-9b2b20218538
TextAutosizer: unlock multipliers on DOMContentLoaded.

This patch unlocks the text autosizing multipliers when
the document has finished parsing. This is necessary
to avoid weird effects when layout changes significantly
during page load. Resetting multipliers allows for a fresh
autosizing pass to take into account the whole document.

In particular this patch fixes issues with overlines on
http://forum.xda-developers.com and partially addresses
inconsistent font size on www.drudgereport.com
(see referenced bugs for details).

BUG=346786,131566

Review URL: https://codereview.chromium.org/189113014

git-svn-id: svn://svn.chromium.org/blink/trunk@169572 bbb929c8-8fbe-4397-9dbb-9b2b20218538
DevTools: cleanup InspectorStyleSheet

This patch cleans up InspectorStyleSheet after the InspectorStyleSheet
and InspectorStyleSheetForInlineStyle implementations were separated.
It does the following changes:
- remove InspectorStyleSheet.checkPageStyleSheet as it is never used
- inline InspectorStyleSheet.ruleIndexByRule
- inline method InspectorStyleSheet.ruleIdByStyle into InspectorStyleSheet.styleId
- introduce single implementation for lineEndings in InspectorStyleSheetBase
- eliminate method InspectorStyleSheetBase.reparsestyleSheet

BUG=341506

Review URL: https://codereview.chromium.org/203633003

git-svn-id: svn://svn.chromium.org/blink/trunk@169574 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove display() from composited scrolling test, mark as failing

This test is testing some paint-dependent behavior (see issue 353827)
and should behave identically whether or not testRunner.display() is
called.  However, without the testRunner.display() calling into paint,
it misses some invalidations that need to be there for correctness.

BUG=345027,353827

Review URL: https://codereview.chromium.org/197883025

git-svn-id: svn://svn.chromium.org/blink/trunk@169575 bbb929c8-8fbe-4397-9dbb-9b2b20218538