[android_webview] Correctly handle ContextWrapper in AwContents.

[android_webview] Correctly handle ContextWrapper in AwContents.

Having a ContextWrapper passed in as the AwContents Context parameter
was causing us to use the wrong kind of window object which in turn
resulted in popup dialogs not being displayed.

BUG=434695
Committed: https://crrev.com/214620e444390c1442a62d79499a82562ebe492d
Cr-Commit-Position: refs/heads/master@{#305796}

[mkosiba (inactive), 2014-11-25 12:56:15]

Patchset #3 (id:40001) has been deleted

[mkosiba (inactive), 2014-11-25 13:46:15]

mkosiba@chromium.org changed reviewers:
+ tedchoc@chromium.org

[mkosiba (inactive), 2014-11-25 13:46:16]

PTAL.

The WebView wraps the Context it gets passed in a ContextWrapper so we can swap
out the ClassLoader. This is why we can't just (context instanceof Activity).

[Ted C, 2014-11-25 18:26:02]

lgtm

[mkosiba (inactive), 2014-11-26 09:59:40]

The CQ bit was checked by mkosiba@chromium.org

[commit-bot: I haz the power, 2014-11-26 10:00:34]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/756983002/20001

[commit-bot: I haz the power, 2014-11-26 10:50:57]

Committed patchset #2 (id:20001)

[commit-bot: I haz the power, 2014-11-26 10:51:35]

Patchset 2 (id:??) landed as
https://crrev.com/214620e444390c1442a62d79499a82562ebe492d
Cr-Commit-Position: refs/heads/master@{#305796}