[android_webview] Use AwContents loadUrl method instead of ContentViewCore.

[android_webview] Use AwContents loadUrl method instead of ContentViewCore.

This introduces a loadUrl method on AwContents and modifies all of
our test code to use that method instead of the on ContentViewCore.

BUG=154558
Java-only change, ran through android FYI.
NOTRY=true

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=161113

[mkosiba (inactive), 2012-10-09 17:19:16]

PTAL

[joth, 2012-10-09 18:44:05]

lgtm.

[benm (inactive), 2012-10-09 19:33:15]

lgtm

[commit-bot: I haz the power, 2012-10-09 20:47:20]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mkosiba@chromium.org/11028094/1

[commit-bot: I haz the power, 2012-10-09 22:41:51]

Change committed as 160959

[mkosiba (inactive), 2012-10-10 09:16:20]

change was reverted... committing one more time

[commit-bot: I haz the power, 2012-10-10 10:19:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/mkosiba@chromium.org/11028094/14001