Merge 184467 "Instant: Don't commit unless the page supports Ins..."

Merge 184467 "Instant: Don't commit unless the page supports Ins..."

> Instant: Don't commit unless the page supports Instant.
> 
> BUG=177948
> R=samarth@chromium.org
> TBR=shishir@chromium.org
> TEST=Follow these steps:
> 1. Install the Google search app.
> 2. Enable Instant from chrome://settings.
> 3. Make sure you are signed in so that http://goto.google.com/instant-redirect works.
> 4. Start chrome with --instant-url="http://goto.google.com/instant-redirect".
> Before: Infinite loop of loading and committing google.com
> After: No infinite loop.
> 
> 
> Review URL: https://chromiumcodereview.appspot.com/12334072

TBR=sreeram@chromium.org
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=187440

[sreeram, 2013-03-12 01:07:31]

Committed patchset #1 manually as r187440.