Fix autoupdate for hosted apps....

Fix autoupdate for hosted apps.

The problem is that CrxInstaller wasn't considering updates when looking for
previously installed apps with overlapping extents.

BUG=68872
TEST=Steps outlined in bug report. 


Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=71818

[asargent_no_longer_on_chrome, 2011-01-19 17:24:09]

http://codereview.chromium.org/6292007/diff/1/chrome/browser/extensions/crx_i...
File chrome/browser/extensions/crx_installer.cc (right):

http://codereview.chromium.org/6292007/diff/1/chrome/browser/extensions/crx_i...
chrome/browser/extensions/crx_installer.cc:314: overlapping_extension->id() !=
extension_->id()) {
Looking at the code before this patch, you'd wonder if update never worked for
hosted apps. It turns out that if you have "*" as the protocol in your extent,
the GetExtensionByOverlappingWebExtent check will return null, so in some cases
update was working. But that seems like a bug for it to return null, so I've
opened a separate bug (70126) to look into that.

[Erik does not do reviews, 2011-01-19 18:21:44]

LGTM