Consistently autosize vBulletin forum comments.

vBulletin forum comments typically use <div id="post_message_*"> to define forum posts. This CL exploits this information and treats all text inside such a "post_message_*" div as autosizable.

This resolves the issue with short comments which do not get autosized by default and often result in annoying layouts with posts having very different font sizes. For efficiency the forum-specific detection code only runs when <meta name="generator" content="vBulletin*"> tag is present.

The described approach does not work for all forums though, so a more elaborate algorithm is required to detect forum comments in general possibly involving extraction of repeating patterns from the DOM tree.

BUG=135947

Review URL: https://chromiumcodereview.appspot.com/23020026

git-svn-id: svn://svn.chromium.org/blink/trunk@157789 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Pass the thumb thickness through for solid color scrollbars.

We were passing in -1 and using the override size on the compositor
side. After we pass the correct value, we can remove the override size
in the compositor.

BUG=None

Review URL: https://chromiumcodereview.appspot.com/23609050

git-svn-id: svn://svn.chromium.org/blink/trunk@157790 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Implement crop rect support for FEComponentTransfer, FEOffset, FEComposite (exluding arithmetic mode), FEFlood.

This will require rebaselines of the indicated tests: some are more correct, some have minor pixel diffs, and some have new test cases (effect-reference-composite.html and effect-reference-composite-hw.html). Although is patch only implements new code in the GPU path, the tests revealed a couple of interesting bugs in the raster path: http://crbug.com/291192, http://crbug.com/291199.

BUG=229910
R=fmalita

Review URL: https://chromiumcodereview.appspot.com/23698008

git-svn-id: svn://svn.chromium.org/blink/trunk@157791 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Removed checkBufferIntegrity, will be done in the command buffer now

BUG=290391

Review URL: https://chromiumcodereview.appspot.com/24129002

git-svn-id: svn://svn.chromium.org/blink/trunk@157792 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add tests for imports in iframe

BUG=240592
R=dominicc,dglazkov

Review URL: https://chromiumcodereview.appspot.com/23933004

git-svn-id: svn://svn.chromium.org/blink/trunk@157793 bbb929c8-8fbe-4397-9dbb-9b2b20218538