Revert of Revert of Add AwAssets into android_webview/native/public

Revert of Revert of Add AwAssets into android_webview/native/public (patchset #1 id:1 of https://codereview.chromium.org/947113002/)

Reason for revert:
https://codereview.chromium.org/950973003/ is just landed to fix the deps problem.

Original issue's description:
> Revert of Add AwAssets into android_webview/native/public (patchset #4 id:70009 of https://codereview.chromium.org/937863003/)
>
> Reason for revert:
> Suspected to cause 'checkdeps' failures on Linux bot:
> http://build.chromium.org/p/chromium.linux/builders/Linux%20Tests/builds/20990/steps/checkdeps/logs/stdio
>
> ERROR in /mnt/data/b/build/slave/Linux_Tests/build/src/android_webview/browser/aw_dev_tools_manager_delegate.cc
>   Illegal include: "android_webview/native/aw_contents.h"
>     Because of "-android_webview" from android_webview/browser's include_rules.
>
> Original issue's description:
> > Add AwAssets into android_webview/native/public
> >
> > This is done so that android_webview/browser doesn't need to depend on
> > android_webview/native
> >
> > BUG=459779
> >
> > Committed: https://crrev.com/a08360b39730751c5f85797bdff5b748d907c11a
> > Cr-Commit-Position: refs/heads/master@{#317475}
>
> TBR=boliu@chromium.org,sgurun@chromium.org,hush@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=459779
>
> Committed: https://crrev.com/34cd1a9f17f7b4509753b0184e7ac3463ab43d13
> Cr-Commit-Position: refs/heads/master@{#317567}

TBR=boliu@chromium.org,sgurun@chromium.org,binjin@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=459779
Committed: https://crrev.com/683d3ba7de29ff2a85b842db2c03faafcc128787
Cr-Commit-Position: refs/heads/master@{#318274}

[hush (inactive), 2015-02-26 18:57:08]

Created Revert of Revert of Add AwAssets into android_webview/native/public

[commit-bot: I haz the power, 2015-02-26 18:58:10]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/957423002/1

[commit-bot: I haz the power, 2015-02-26 18:59:11]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-02-26 18:59:56]

Patchset 1 (id:??) landed as
https://crrev.com/683d3ba7de29ff2a85b842db2c03faafcc128787
Cr-Commit-Position: refs/heads/master@{#318274}