Revert of Fix to remove customised String over IPC for SmartClip

Revert of Fix to remove customised String over IPC for SmartClip (https://codereview.chromium.org/259263003/)

Reason for revert:
android build was broken by this patch
http://build.chromium.org/p/chromium.webkit/builders/Android%20Builder/builds/39026/steps/compile/logs/stdio

Original issue's description:
> Fix to remove customised String over IPC for SmartClip
> 
> Currently, the data for SmartClip is sent over IPC as a customized
> string, which contains rect values and string of content within the
> clip rect. Changes from Blink side to remove custom serialization and
> send it as a structure of rect and string values.
> 
> BUG=330872
> 
> Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=173295

TBR=eseidel@chromium.org,juhui24.lee@samsung.com,abarth@chromium.org,jam@chromium.org,jschuh@chromium.org,ch.dumez@samsung.com,avi.nitk@samsung.com
NOTREECHECKS=true
NOTRY=true
BUG=330872
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=173296

[loislo, 2014-05-05 12:14:28]

Created Revert of Fix to remove customised String over IPC for SmartClip

[commit-bot: I haz the power, 2014-05-05 12:14:43]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/loislo@chromium.org/266193003/1

[commit-bot: I haz the power, 2014-05-05 12:15:15]

Change committed as 173296