Revert of Avoid unnecessary descents into nested boxes with floats. (https://codereview.chromium.org/195363007/)

Reason for revert:
Caused a lot of float crashes in ClusterFuzz
https://code.google.com/p/chromium/issues/detail?id=357242

Original issue's description:
> Avoid unnecessary descents into nested boxes with floats.
> 
> Steal a bit from RenderBlock to avoid descending through the same
> stack of nested boxes multiple times while preparing to lay them out.
> 
> 
> This CL creates a 4% improvement in the 
> Performance/Layout/floats_*_nested.html tests.
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=170060

TBR=ojan@chromium.org,leviw@chromium.org,bjonesbe@adobe.com,jchaffraix@chromium.org
NOTREECHECKS=true
NOTRY=true

Review URL: https://codereview.chromium.org/214523007

git-svn-id: svn://svn.chromium.org/blink/trunk@170194 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Returning IntSize to store calculated kernel size values
allows to have less function paramenters. This patch also
streamlines a bit the code in calculateUnscaledKernelSize.

BUG=356329

Review URL: https://codereview.chromium.org/211513003

git-svn-id: svn://svn.chromium.org/blink/trunk@170195 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Change UnsafePersistent<.> to Eternal<.> in V8PerIsolateData.
This is split out from 206533004, as it's largely unrelated to
the remaining changes there.

BUG=

Review URL: https://codereview.chromium.org/212793013

git-svn-id: svn://svn.chromium.org/blink/trunk@170196 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Test resampling of AudioBuffers that have a different sample rate from the context

This is a follow up that adds a simple layout test to test
https://codereview.chromium.org/201673004/

This test creates an audio context at 48 kHz and a 3 kHz sine wave in
an AudioBuffer that is played through the context. The test verifies
that the output is sufficiently close to the expected sine wave output.

BUG=344375

Review URL: https://codereview.chromium.org/213153003

git-svn-id: svn://svn.chromium.org/blink/trunk@170197 bbb929c8-8fbe-4397-9dbb-9b2b20218538