Fix browser crash when refreshing extensions....

Fix browser crash when refreshing extensions.

If you have two extensions with page actions, you can get into
a state where it crashes if you refresh Extension A, then
Extension B and Extension A again.

BUG=http://crbug.com/44415
TEST=Covered by new test ExtensionBrowserTest.PageActionRefreshCrash



Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=47722

[Matt Perry, 2010-05-19 20:21:44]

LGTM. Good detective work.

http://codereview.chromium.org/2134008/diff/1/5
File chrome/test/data/extensions/browsertest/crash_44415/ExtA/background.html
(right):

http://codereview.chromium.org/2134008/diff/1/5#newcode4
chrome/test/data/extensions/browsertest/crash_44415/ExtA/background.html:4:
chrome.tabs.onUpdated.addListener(function(tabId)
Where does this onUpdated event come from? The test doesn't seem to navigate
anywhere. Would it be better to just use tabs.getSelected() ?

[Finnur, 2010-05-19 20:45:50]

> Where does this onUpdated event come from? The test doesn't
> seem to navigate anywhere. Would it be better to just use
> tabs.getSelected() ?

Ah, thanks for pointing that out. I had forgotten to actually clean up the test
extensions I used to generate the crash. I also made them guaranteed to be
visible before testing, which is not required for the test, but might become so
if we change the code -- given that this is in the code to show the page action
icons.

PTAL.

[Matt Perry, 2010-05-19 21:02:03]

LGTM