Revert of Makes ScrollbarTheme call through to theme engine for corner (https://codereview.chromium.org/149093009/)

Reason for revert:
Broke Android Tests (dbg)/webkit_unittests:

[FATAL:webthemeengine_impl_android.cc(37)] Check failed: false. 

http://build.chromium.org/p/chromium.webkit/builders/Android%20Tests%20%28dbg%29

Original issue's description:
> Makes ScrollbarTheme call through to theme engine for corner
> 
> Hopefully the last bit of wiring needed to let the theme engine draw
> the corner.
> 
> BUG=333499
> TEST=none
> R=jamesr@chromium.org
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=166511

TBR=jamesr@chromium.org,sky@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=333499

Review URL: https://codereview.chromium.org/156163004

git-svn-id: svn://svn.chromium.org/blink/trunk@166552 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove provisional entry clearing hack in HistoryController.

This was a temporary hack designed to fix a bug in a way that would also
work on the 1750 branch. The cleaner and more correct solution is to never
try to clear HistoryController::m_provisionalEntry and trust goToEntry() to
ensure that no stale provisional entry will be left around after starting
a new provisonal load.

BUG=338480
TEST=WebFrameTest.BackDuringChildFrameReload should still pass

Review URL: https://codereview.chromium.org/143383008

git-svn-id: svn://svn.chromium.org/blink/trunk@166555 bbb929c8-8fbe-4397-9dbb-9b2b20218538
StyleInvalidationAnalysis cannot use selector scope for ^ and ^^ rules.

TEST=fast/dom/shadow/dynamically-added-cat-hat-rules.html
BUG=339657

Review URL: https://codereview.chromium.org/136643004

git-svn-id: svn://svn.chromium.org/blink/trunk@166556 bbb929c8-8fbe-4397-9dbb-9b2b20218538
CGI scripts currently specify a mix of 'perl -w' and 'perl -wT'; fix that.

In order to run the Win32 Apache and be able to reuse the existing
CGI scripts in the tests, we have to jump through some hoops and those
hoops do not support having mixed command lines in the shebang lines for
a given executable.

R=scottmg@chromium.org
BUG=30536

Review URL: https://codereview.chromium.org/153913005

git-svn-id: svn://svn.chromium.org/blink/trunk@166557 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Test focus behavior for off-screen SVGAElements

This CL adds a test that was missing in
https://codereview.chromium.org/138793005/. The test wasn't included in the
original CL because another CL had to land later in order to make the change
easily testable.

R=pdr@chromium.org

Review URL: https://codereview.chromium.org/156093003

git-svn-id: svn://svn.chromium.org/blink/trunk@166558 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Rewrite to not store type in m_type and also remove type getter/setter.

Make sure SVGScriptElement can use fastGetAttribute for attribute "type" by overriding isAnimatableAttribute. Now we can use Reflect to access type from js and can remove m_type.

Review URL: https://codereview.chromium.org/113133002

git-svn-id: svn://svn.chromium.org/blink/trunk@166559 bbb929c8-8fbe-4397-9dbb-9b2b20218538
PartitionAlloc: increase alignment in Debug builds again.

The minimum alignment that our Debug cookies imply is now 16. This caters for
XMM instructions on Intel.

Review URL: https://codereview.chromium.org/141703031

git-svn-id: svn://svn.chromium.org/blink/trunk@166560 bbb929c8-8fbe-4397-9dbb-9b2b20218538