Windows file associations: Search for shim in Chrome version directory.

Windows file associations: Search for shim in Chrome version directory.

Previously, would search for app_shim.exe in the Chrome application
directory, for example:

C:\Program Files\Google\Chrome\Application

Now searches in the Chrome version directory, for example:

C:\Program Files\Google\Chrome\Application\42.0.2277.0

which is where all version-specific files should be stored.

Note: The installer does not currently place app_shim.exe anywhere, so
we do not need to update its location. Users who have manually copied
app_shim.exe into the application directory will need to move it into
the version directory after this change.

Also gives a better error message if app_shim.exe is not found.

BUG=430760
Committed: https://crrev.com/8a3b08cdba3c4ea2afce430f24c356e3e08666de
Cr-Commit-Position: refs/heads/master@{#311800}

[Matt Giuca, 2015-01-15 23:15:29]

mgiuca@chromium.org changed reviewers:
+ jackhou@chromium.org

[jackhou1, 2015-01-15 23:19:49]

lgtm

[Matt Giuca, 2015-01-15 23:23:06]

The CQ bit was checked by mgiuca@chromium.org

[Matt Giuca, 2015-01-15 23:23:17]

What service!

[commit-bot: I haz the power, 2015-01-15 23:23:32]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/838793004/1

[commit-bot: I haz the power, 2015-01-16 00:55:45]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-01-16 00:56:33]

Patchset 1 (id:??) landed as
https://crrev.com/8a3b08cdba3c4ea2afce430f24c356e3e08666de
Cr-Commit-Position: refs/heads/master@{#311800}