[Repaint-after-layout] Remove triggering ASSERT

https://codereview.chromium.org/258693002/ landed an ASSERT
that happened to be triggering on some tests. The reason is
that for a layout where the root is not the view, we could
have positioned objects that belong to a containing block
higher in the tree than the layout root.

The optimization could be fixed but it would involve calling
isDescendantOf, which can be expensive (walking the tree up
to the root repeatedly), and it will get in the way of any
optimizations that avoids calling repaintTreeAfterLayout.
Thus it's more simple to just remove it.

Review URL: https://codereview.chromium.org/257943002

git-svn-id: svn://svn.chromium.org/blink/trunk@172785 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Avoid repaints on subpixel layer location change

Previously, we accumulate subpixel offset in range of [0, 1) (in x or y
direction). If accumulatedSubpixelOffset >= 0.5, we will add 1 to
offsetFromRenderer of the composited layer, causing full repaint of the
layer.

This causes frequent repaints when the layer animates its location.

This CL changes accumulated subpixel offset range to [-0.5, 0.5) to
avoid change of offsetFromRenderer during location animation.

The method doesn't ensure the accurate positioning of contents of the
composited layer (which seems impossible -- see the bug), but not worse
than the original method.

Added tests in fast/sub-pixel/repaint-subpixel-layer-in-subpixel-composited-layer.html.
The errors of left of the inner div before and after this CL for each
test case in the test are:
         Before    After
case 1    0         1
case 2   -1         0
case 3    0         0
case 4    0         1
case 5   -1        -1
(error = <physical left of the inner div when the outer div is composited>
       - <physical left of the inner div when the outer div is not composited>)

BUG=308737
TEST=fast/sub-pixel/should-not-repaint-subpixel-composited-layer.html
TEST=fast/sub-pixel/repaint-subpixel-layer-in-subpixel-composited-layer.html

Review URL: https://codereview.chromium.org/259893003

git-svn-id: svn://svn.chromium.org/blink/trunk@172786 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Gardening: Tweak expected failure type for svg test

TBR=enne@chromium.org,davve@opera.com
BUG=367846
NOTRY=true

Review URL: https://codereview.chromium.org/260083003

git-svn-id: svn://svn.chromium.org/blink/trunk@172787 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Identify viewports that trigger GPU rasterization

This adds a hasViewportThatTriggersGpuRasterization
method to WebView. The return value of this method
depends on the presence of the meta tag
<meta name="viewport" content="width=device-width, minimum-scale=1.0, minimal-ui">

BUG=367202

Review URL: https://codereview.chromium.org/259683002

git-svn-id: svn://svn.chromium.org/blink/trunk@172788 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Prepare LayoutTests for making data: urls async

I've just about given up on making data urls async
for now, given the trouble I've had with browser_tests.
But I'm at least going to commit these changes
which prepare LayoutTests for making data urls async
at a future time.

BUG=308321, 365509

Review URL: https://codereview.chromium.org/258713015

git-svn-id: svn://svn.chromium.org/blink/trunk@172789 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[CSS Shapes] Add parsing support for gradients

Added support for shape-outside gradient values.

This is a merge of http://trac.webkit.org/changeset/167518 by Hans Muller <hmuller@adobe.com>.

BUG=322165

Review URL: https://codereview.chromium.org/244693003

git-svn-id: svn://svn.chromium.org/blink/trunk@172790 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Gardening: mark web-animations-api/timeline-time.html as flaky

TBR=ericwilligers@chromium.org
BUG=367903
NOTRY=true

Review URL: https://codereview.chromium.org/251133003

git-svn-id: svn://svn.chromium.org/blink/trunk@172791 bbb929c8-8fbe-4397-9dbb-9b2b20218538
[FastTextAutosizer] Remove isFingerprintingCandidate and nextChildSkippingChildrenOfBlocks

This trivial patch removes two declarations that have no implementaiton.

BUG=

Review URL: https://codereview.chromium.org/259763006

git-svn-id: svn://svn.chromium.org/blink/trunk@172792 bbb929c8-8fbe-4397-9dbb-9b2b20218538