Fix chrome_url_overides to work with packed extensions.

Fix chrome_url_overides to work with packed extensions.
The InitFromValue code was modifying the JSON with some local data which
was then being re-used by the unpacker and sent up to the browser which 
caused it to use this temporary local data as if it was the original 
manifest source.

BUG=24398
TEST=pack and install override_igoogle extension

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=29376

[Matt Perry, 2009-10-16 22:59:35]

Mostly LGTM.

As for verifying that people don't make this mistake in the future, we could do
something like:
  scoped_ptr<DictionaryValue> orig_manifest(manifest->DeepCopy());
at the top of InitFromValue, and
  DCHECK(orig_manifest->Equals(manifest));
at the end.

http://codereview.chromium.org/276074/diff/1/4
File chrome/common/extensions/extension.cc (right):

http://codereview.chromium.org/276074/diff/1/4#newcode1020
Line 1020: override_map urls;
You could probably just do
   overrides = overrides->DeepCopy()
here for the easy way out. But using a map seems cleaner.

http://codereview.chromium.org/276074/diff/1/5
File chrome/common/extensions/extension.h (right):

http://codereview.chromium.org/276074/diff/1/5#newcode29
Line 29: typedef std::map<const std::string, GURL> override_map;
OverrideMap (or maybe even URLOverrideMap)

[Erik does not do reviews, 2009-10-16 23:29:19]

addressed your feedback

[Matt Perry, 2009-10-16 23:29:23]

LGTM