Retry channel setup for NPAPI plugins.

Retry channel setup for NPAPI plugins.

For the referenced bugs, assume that an undiscovered Mr X is closing
the channels, but that the closing is not 100% persistent.  So retry
the setup.

For cases where everything works, this is a non-event, the first time
through will get the channel.  It only kicks in for cases where the
plugin is either going to show a failure infobar, or would previously
have crashed (the 97285 case).  So this doesn't seem like it has a
strong downside.

BUG=97285, 141055
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=152730

[Scott Hess - ex-Googler, 2012-08-20 22:26:32]

Apologies that the diff sucks so bad - with a local 'git diff -w master', things
look much cleaner.  So it might be reasonable to patch it locally and use a diff
tool that can ignore whitespace changes.

Anyhow, gist of it is "Try harder".  I picked 2 under the assumption that if it
happens 1-in-N times, now it's 1-in-N*N.  I don't think there would be all that
much downside to using 3 or 4.

I'm wondering if it would be even better with histograms.  I would certainly
feel more comfortable if we could track how often it hits each case and whether
failure falls off with retries or not.

[Bernhard Bauer, 2012-08-20 22:52:26]

LGTM. Histograms sound like a good idea.

[piman, 2012-08-20 23:35:31]

lgtm

[Scott Hess - ex-Googler, 2012-08-21 21:54:59]

I'm going to push commit and land histograms later.  Principled argument is that
then I can merge the change to a branch easily without the histograms. 
Unprincipled argument is that waiting for histograms will lose another day or
two, depending on interrupt load.

[commit-bot: I haz the power, 2012-08-21 21:57:06]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/10824388/1

[commit-bot: I haz the power, 2012-08-21 21:57:11]

Failed to apply patch for content/renderer/webplugin_delegate_proxy.cc:
While running patch -p1 --forward --force;
patching file content/renderer/webplugin_delegate_proxy.cc
Hunk #1 FAILED at 277.
1 out of 1 hunk FAILED -- saving rejects to file
content/renderer/webplugin_delegate_proxy.cc.rej

[commit-bot: I haz the power, 2012-08-21 22:57:56]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/shess@chromium.org/10824388/3002

[commit-bot: I haz the power, 2012-08-22 04:10:57]

Change committed as 152730