Add Blink-side flag for enabling/disabling layer squashing.

Add Blink-side flag for enabling/disabling layer squashing.

default is off.

BUG=315317
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=162497

[shawnsingh, 2013-11-19 00:55:52]

jamesr@ for Source/web/ and public/web/
vollick@ for Source/core/

PTAL, thanks!

[Ian Vollick, 2013-11-19 02:30:01]

On 2013/11/19 00:55:52, shawnsingh wrote:
> jamesr@ for Source/web/ and public/web/
> vollick@ for Source/core/
> 
> PTAL, thanks!

lgtm.

[shawnsingh, 2013-11-20 01:33:07]

jamesr@  can you please review/stamp for Source/web/ and public/web?  Just
adding a flag for layer squashing.   Thanks in advance.

[jochen (gone - plz use gerrit), 2013-11-20 09:00:32]

can you add layout tests for this (since you added it to internal.settings
already it should be easy)

[shawnsingh, 2013-11-20 18:14:01]

On 2013/11/20 09:00:32, jochen wrote:
> can you add layout tests for this (since you added it to internal.settings
> already it should be easy)

There is actually no implementation of squashing that needs to use this flag
yet.  I'm planning to land pieces of it immediately next.  Ian is likely to help
me with adding layout tests to cover the squashing feature, too.  You can see a
roadmap of what I'm doing here: 
https://docs.google.com/a/chromium.org/document/d/1eYVFvIO9JiXFXIPu1Dr7aAxX1u...

All of this hinges on adding the flag first, though.  I did verify manually with
hacks that this flag will work on linux desktop layout tests.  Please let me
know if I am missing what you meant =)

[jochen (gone - plz use gerrit), 2013-11-21 13:17:43]

lgtm

[commit-bot: I haz the power, 2013-11-21 21:57:50]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shawnsingh@chromium.org/75823002/130001

[commit-bot: I haz the power, 2013-11-21 23:59:57]

Change committed as 162497