Pass the ImageSkia by pointer instead of by reference, which will create shallow copy.

- Pass the ImageSkia by pointer instead of by reference, which will create shallow copy of the deep copyed image skia.
This changes ImageSkia::DeepCopy to return scoped_ptr<ImageSkia> so that i can safely transfer ownership without creating shallow copy of ImageSkia.

- Make sure all image reps are generated before passing to anther thread.

This is hypothetical fix for 159557

BUG=159557
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=167390

[pkotwicz, 2012-11-07 06:48:50]

LGTM for M23, I would like to find a simpler way to do this for M25

[pkotwicz, 2012-11-07 17:09:45]

Btw, not necessarily as part of this CL, can you write a test demonstrating how
a crash can occur as a result of non thread safe refcounting and base::Bind().
This would help me understand the issue better

[bshe, 2012-11-07 17:19:51]

On 2012/11/07 17:09:45, pkotwicz wrote:
> Btw, not necessarily as part of this CL, can you write a test demonstrating
how
> a crash can occur as a result of non thread safe refcounting and base::Bind().
> This would help me understand the issue better

lgtm

[oshima, 2012-11-07 18:38:07]

On 2012/11/07 17:09:45, pkotwicz wrote:
> Btw, not necessarily as part of this CL, can you write a test demonstrating
how
> a crash can occur as a result of non thread safe refcounting and base::Bind().
> This would help me understand the issue better

This is race condition on refcount object, and it's very difficult to write good
test that can
verify it. It is, however, possible to make RefCounted to be a NonThreadSafe and
do DCHECK if it's
accessed from valid thread. It's very likely that there are valid violations,
and I'm not sure if it's feasible to do so. Another possibility is tsan, which
we currently don't
have for chromeos. I'll work on tsan (which we should have it anyway) first.

[oshima, 2012-11-07 20:58:48]

ben -> ui/ OWNERS

[oshima, 2012-11-09 22:39:36]

ben is OOO. scott, could you please review this?

[sky, 2012-11-09 23:04:56]

LGTM

[commit-bot: I haz the power, 2012-11-09 23:09:53]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11361131/1

[commit-bot: I haz the power, 2012-11-10 00:13:13]

Sorry for I got bad news for ya.
Compile failed with a clobber build on win.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win&number...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[commit-bot: I haz the power, 2012-11-10 15:50:03]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11361131/1009

[commit-bot: I haz the power, 2012-11-13 14:32:21]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/oshima@chromium.org/11361131/1009

[commit-bot: I haz the power, 2012-11-13 14:39:40]

Change committed as 167390