[Tracing] Add support for forward looking or backwards looking async steps. 

Renamed TRACE_EVENT_ASYNC_STEP to TRACE_EVENT_ASYNC_STEP_INTO and 
added TRACE_EVENT_ASYNC_STEP_PAST. These are mutually exclusive. Users 
must decide all of their steps are backwards or forwards looking for an 
async event. 

Updated callers to use the correct versions.

BUG=None
TBR=acolwell

Review URL: https://codereview.chromium.org/23484030

git-svn-id: svn://svn.chromium.org/blink/trunk@161964 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Created test for testing repaint rects for elements inside relative-positioned regions.

BUG=249715

Review URL: https://codereview.chromium.org/71603002

git-svn-id: svn://svn.chromium.org/blink/trunk@161965 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove RenderingConfiguration, it's dead code

The parallel layout effort will wait for another day.
This code never really ended up being used
and so I'm removing it.

Added in:
https://chromiumcodereview.appspot.com/23866009

R=abarth,ojan
BUG=289678

Review URL: https://codereview.chromium.org/59813006

git-svn-id: svn://svn.chromium.org/blink/trunk@161966 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Update the usage of SkImage::Info (deprecated) in Canvas2DLayerBridge.

SkImage::Info is deprecated, we should switch to SkImageInfo.

BUG=None
TEST=None
R=senorblanco@chromium.org

Review URL: https://codereview.chromium.org/61763023

git-svn-id: svn://svn.chromium.org/blink/trunk@161967 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add some shrinkToFit calls missing in recent patches.

Review URL: https://codereview.chromium.org/59883012

git-svn-id: svn://svn.chromium.org/blink/trunk@161968 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Have ElementTraversal::firstWithin() take a reference

Have ElementTraversal::firstWithin() take a reference instead of a pointer
as its implementation expects the pointer to be non-null. This makes the
code look safer.

R=adamk

Review URL: https://codereview.chromium.org/68173014

git-svn-id: svn://svn.chromium.org/blink/trunk@161969 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[Android WebView] Fix UA initial scale clobber code

A follow-up for https://codereview.chromium.org/55073002/

Apparently, the committed conditions for clobbering the UA-specified
initial scale were not matching the CL description :)

I have also noticed that, depending on ViewportMetaLayoutSizeQuirk state,
width's ExtendToZoom type may or may not be converted into Auto,
so I extended existing checks for 'isAuto' with checks for 'ExtendToZoom'.

BUG=304548, 313754

Review URL: https://codereview.chromium.org/69933011

git-svn-id: svn://svn.chromium.org/blink/trunk@161970 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Web Animations CSS: Fix clamping to non-negative values for BorderImageLength

Also beef up a number of tests that use this code

BUG=257591
R=alancutter@chromium.org, alancutter

Review URL: https://codereview.chromium.org/54123007

git-svn-id: svn://svn.chromium.org/blink/trunk@161971 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Move ScopedStyleTree into it's own file.

Makes the code easier to navigate and gives better separation
of concerns.

Review URL: https://codereview.chromium.org/70103008

git-svn-id: svn://svn.chromium.org/blink/trunk@161972 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Use a boolean hasCompositedLayerMapping() accessor instead of the pointer

In order to add the ability to paint multiple RenderLayers into one
composited layer backing, we need to complexity the possible "states"
that a RenderLayer identifies as its compositingState. There are many
places in code that still use compositedLayerMapping() as a boolean
accessor to indicate compositingState, but doing so now is already
inadequate, and with layer squashing, it may even be wrong in many
places.

To gradually evolve the codebase away from the compositedLayerMapping()
accessor as a boolean, it is helpful to create a boolean accessor,
hasCompositedLayerMapping(). The purpose of doing this is to more easily
distinguish between places in code where compositedLayerMapping() is
actually used as an object versus places where it is used as a boolean.

BUG=261605

Review URL: https://codereview.chromium.org/58543002

git-svn-id: svn://svn.chromium.org/blink/trunk@161973 bbb929c8-8fbe-4397-9dbb-9b2b20218538