Remove implicit conversions from scoped_refptr to T* in android_webview/

Remove implicit conversions from scoped_refptr to T* in android_webview/

This patch was generated by running the rewrite_scoped_refptr clang tool
on an Android build.

BUG=110610
Committed: https://crrev.com/4cb42ab619d962bd0a0c0bf23f60bf2c26add29b
Cr-Commit-Position: refs/heads/master@{#298503}

[dcheng, 2014-10-06 22:36:16]

dcheng@chromium.org changed reviewers:
+ benm@chromium.org

[benm (inactive), 2014-10-07 13:08:51]

lgtm

[dcheng, 2014-10-07 16:14:28]

The CQ bit was checked by dcheng@chromium.org

[commit-bot: I haz the power, 2014-10-07 16:15:48]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/634583004/1

[commit-bot: I haz the power, 2014-10-07 16:41:30]

Committed patchset #1 (id:1) as 200b840b42cab1192a5d99d51a0da4a2bb8ff0f8

[commit-bot: I haz the power, 2014-10-07 16:42:12]

Patchset 1 (id:??) landed as
https://crrev.com/4cb42ab619d962bd0a0c0bf23f60bf2c26add29b
Cr-Commit-Position: refs/heads/master@{#298503}