Add limitation that LoadNexeAndStart must be called on the main thread.

Add limitation that LoadNexeAndStart must be called on the main thread.

Now we're switching LoadNexeAndStart from synchronous implementation to
asynchronous one. Under PPAPI implementation, the async callbacks are
handled on main thread.
To keep the similicity of the thread model, this CL introduces the limitation
that Plugin::LoadNexeAndStart must be called on the main thread.

TEST=Ran browser_tests --gtest_filter=NaCl* locally and trybots.
BUG=333950
R=teravest@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=276371

[hidehiko, 2014-06-10 06:55:33]

Hi Justin,
could you take a look?

This is the CL to run LoadNexeAndStart on the main thread, which I mentioned in
crrev.com/326593002's review.

Note: I manually copied some code from crrev.com/326593002 to keep the code
simplicity, because otherwise we hit the limit of the number of arguments of
ppapi's NewCallback implementation. Rebasing (in either way) should resolve the
duplication very easily. I'll do it once either one is checked in.
If you think the copied part is not acceptable, please feel free to suspend
until it is resolved. I'll address it.

Please let me send this now to utilize the time, as we have timezone gap.

Thank you for your review in advance,
- hidehiko

[teravest, 2014-06-10 15:19:25]

lgtm

https://codereview.chromium.org/321053004/diff/1/ppapi/native_client/src/trus...
File ppapi/native_client/src/trusted/plugin/plugin.h (right):

https://codereview.chromium.org/321053004/diff/1/ppapi/native_client/src/trus...
ppapi/native_client/src/trusted/plugin/plugin.h:169: void
LoadNexeAndStart(int32_t pp_error,
Please add a comment like the following:
  " // This is invoked on the main thread"

[hidehiko, 2014-06-11 07:24:20]

The CQ bit was checked by hidehiko@chromium.org

[hidehiko, 2014-06-11 07:24:21]

The CQ bit was unchecked by hidehiko@chromium.org

[hidehiko, 2014-06-11 07:24:37]

Thank you for review. Submitting...

https://codereview.chromium.org/321053004/diff/1/ppapi/native_client/src/trus...
File ppapi/native_client/src/trusted/plugin/plugin.h (right):

https://codereview.chromium.org/321053004/diff/1/ppapi/native_client/src/trus...
ppapi/native_client/src/trusted/plugin/plugin.h:169: void
LoadNexeAndStart(int32_t pp_error,
On 2014/06/10 15:19:25, teravest wrote:
> Please add a comment like the following:
>   " // This is invoked on the main thread"

Done.

[hidehiko, 2014-06-11 07:24:41]

The CQ bit was checked by hidehiko@chromium.org

[commit-bot: I haz the power, 2014-06-11 07:30:39]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/hidehiko@chromium.org/321053004/40001

[hidehiko, 2014-06-11 12:55:19]

Committed patchset #3 manually as r276371 (presubmit successful).