Revert of 2D canvas: remain in deferred rendering mode with canvas to canvas drawImage

Revert of 2D canvas: remain in deferred rendering mode with canvas to canvas drawImage (patchset #2 id:20001 of https://codereview.chromium.org/1288773005/ )

Reason for revert:
Appears to be triggering MSAN crashes: http://test-results.appspot.com/dashboards/flakiness_dashboard.html#tests=virtual%2Fdisplay_list_2d_canvas%2Ffast%2Fcanvas%2F2d.composite.globalAlpha.fillPath.html&testType=layout-tests

Original issue's description:
> 2D canvas: remain in deferred rendering mode with canvas to canvas drawImage
> 
> If the source canvas is not animated, no need to exit deferred rendering
> because there is no risk of memory bloat due to snapshotting.
> 
> BUG=521001
> TEST=telemetry tough_canvas_cases
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200654

TBR=senorblanco@chromium.org,junov@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=521001
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=200660

[leviw_travelin_and_unemployed, 2015-08-17 19:01:25]

Created Revert of 2D canvas: remain in deferred rendering mode with canvas to
canvas drawImage

[commit-bot: I haz the power, 2015-08-17 19:01:44]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1295673003/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1295673003/1

[commit-bot: I haz the power, 2015-08-17 19:02:14]

Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200660

[leviw_travelin_and_unemployed, 2015-08-17 20:11:58]

On 2015/08/17 at 19:02:14, commit-bot wrote:
> Committed patchset #1 (id:1) as
https://src.chromium.org/viewvc/blink?view=rev&revision=200660

The test recovered after this revert.

[Justin Novosad, 2015-08-17 20:13:59]

On 2015/08/17 20:11:58, leviw wrote:
> On 2015/08/17 at 19:02:14, commit-bot wrote:
> > Committed patchset #1 (id:1) as
> https://src.chromium.org/viewvc/blink?view=rev&revision=200660
> 
> The test recovered after this revert.

Yep, re-land+fix is on the verge: https://codereview.chromium.org/1289423003/