Fix extension content verification handling of ./ in icon paths

Fix extension content verification handling of ./ in icon paths

When extension manifests contain icon paths with a leading ./, we
were failing to process them properly

BUG=410666
Committed: https://crrev.com/7cc29ce343a235f9067545ddd19ba2d982c4595f
Cr-Commit-Position: refs/heads/master@{#298979}

[asargent_no_longer_on_chrome, 2014-10-07 16:55:50]

asargent@chromium.org changed reviewers:
+ rockot@chromium.org

[Ken Rockot(use gerrit already), 2014-10-07 17:25:51]

https://codereview.chromium.org/630243002/diff/20001/extensions/browser/conte...
File extensions/browser/content_verifier.cc (right):

https://codereview.chromium.org/630243002/diff/20001/extensions/browser/conte...
extensions/browser/content_verifier.cc:219: for (const auto& image_path :
browser_images) {
YAY AUTO

https://codereview.chromium.org/630243002/diff/20001/extensions/browser/conte...
extensions/browser/content_verifier.cc:221: image_path.DirName() ==
relative_path.DirName()) {
Discussed offline, but probably want to compare individual components with
GetComponents, as DirName will only return the penultimate component.

[asargent_no_longer_on_chrome, 2014-10-08 17:49:57]

Ok, PTAL.

I switched to transforming the browser icon paths we get at extension load time
and store for comparison purposes on the IO thread to be properly relative, e.g.

"./foo/icon.png" or "/foo/icon.png"

will be transformed to

"foo/icon.png"

which we later compare against actual relative paths in the filesystem. 

I also made a small change to reduce copying of these modified FilePath's.

[asargent_no_longer_on_chrome, 2014-10-08 17:50:34]

Oh one more thing too - I added the source to the dot_slash_paths.crx extension,
even though it isn't used in the test, so that you can see the various test
cases for paths I have in the manifest file.

[asargent_no_longer_on_chrome, 2014-10-09 19:23:01]

New version up which fixes the two problems on windows: the FILE_PATH_LITERAL
compile error and the problem with \ vs / as path separator.

[Ken Rockot(use gerrit already), 2014-10-09 19:51:49]

lgtm

[asargent_no_longer_on_chrome, 2014-10-09 19:53:16]

The CQ bit was checked by asargent@chromium.org

[commit-bot: I haz the power, 2014-10-09 19:54:23]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/630243002/80001

[commit-bot: I haz the power, 2014-10-09 20:03:00]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2014-10-09 20:03:02]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)
  mac_chromium_compile_dbg on tryserver.chromium.mac
(http://build.chromium.org/p/tryserver.chromium.mac/builders/mac_chromium_comp...)

[asargent_no_longer_on_chrome, 2014-10-09 20:11:25]

The CQ bit was checked by asargent@chromium.org

[commit-bot: I haz the power, 2014-10-09 20:12:37]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/630243002/290001

[commit-bot: I haz the power, 2014-10-09 21:28:08]

Committed patchset #6 (id:290001)

[commit-bot: I haz the power, 2014-10-09 21:28:56]

Patchset 6 (id:??) landed as
https://crrev.com/7cc29ce343a235f9067545ddd19ba2d982c4595f
Cr-Commit-Position: refs/heads/master@{#298979}