Remove frame flattening from rendering code.

Remove frame flattening from rendering code.

Chromium never enables frame flattening; we can simplify frame rendering by
removing the various paths that only execute if flattening is enabled.

Currently, this patch leaves RenderFrameBase as an empty shell. We will
remove that entirely in a subsequent patch.

This is a reland of a reland of a reland. It's totally going to work this time.
Carrying over Ojan's LGTM from the original patch: https://codereview.chromium.org/13877010

BUG=231902
TBR=ojan

Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=150495

[Mike West, 2013-05-14 08:33:03]

https://codereview.chromium.org/14614007/diff/3001/Source/core/page/FrameView...
File Source/core/page/FrameView.cpp (right):

https://codereview.chromium.org/14614007/diff/3001/Source/core/page/FrameView...
Source/core/page/FrameView.cpp:916: if (!m_nestedLayoutCount &&
!m_inSynchronousPostLayout && m_postLayoutTasksTimer.isActive() &&
!frame()->document()->shouldDisplaySeamlesslyWithParent()) {
We missed this last time. inChildFrameLayoutWithFrameFlattening was true if the
frame was seamless.

[kenneth.christiansen, 2013-05-14 08:37:30]

lgtm, let's hope this passes!

[Mike West, 2013-05-14 10:51:12]

Jochen, would you mind taking a look at the single Source/WebKit change?

[jochen (gone - plz use gerrit), 2013-05-14 11:01:06]

lgtm

[Mike West, 2013-05-14 11:44:22]

*sigh* It would be nice if the trybots were at all helpful. :/

[Mike West, 2013-05-16 07:48:04]

On 2013/05/14 11:44:22, Mike West (chromium) wrote:
> *sigh* It would be nice if the trybots were at all helpful. :/

Alright. Both debug and release bots are happy. I screenshotted it and
everything. :)

Let's see what the CQ says.

[commit-bot: I haz the power, 2013-05-16 07:50:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mkwst@chromium.org/14614007/15001

[commit-bot: I haz the power, 2013-05-16 08:16:37]

Change committed as 150495