Do not commit InstantLoader server redirects till the page supports instant.

chrome/browser/instant/instant_controller.cc

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/instant/instant_controller.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/string_util.h"
 #include "base/utf_string_conversions.h"
@@ skipping 851 matching lines @@
 
 void InstantController::InstantLoaderRenderViewGone() {
   ++blacklisted_urls_[loader_->instant_url()];
   HideInternal();
   delete loader_->ReleaseContents();
   // Delay deletion as we have gotten here from an InstantLoader method.
   MessageLoop::current()->DeleteSoon(FROM_HERE, loader_.release());
   CreateDefaultLoader();
 }
 
-void InstantController::InstantLoaderAboutToNavigateMainFrame(const GURL& url) {
+void InstantController::InstantLoaderAboutToNavigateMainFrame(
+    const GURL& url,
+    bool is_server_redirect) {
   GURL instant_url(loader_->instant_url());
 
+  // If the page does not yet support instant, we allow redirects to go through
+  // since the instant URL can redirect - e.g. to country specific pages.
+  if (!loader_->supports_instant() && is_server_redirect)
+    return;

[sreeram, 2013/01/08 00:50:03]

Put this before the GURL declaration above, so we avoid the object construction
if this condition is hit.

Also, do we really need to have this bool passed to us? What would go wrong if
we just did this:

if (!loader_->supports_instant())
  return;

If that works, you can get rid of all the other code in this CL, no?

[Shishir, 2013/01/08 01:01:12]

Forgot that the instant page had to call show to show up initially.

All Done.

+
   // If we are navigating to the instant URL, do nothing.
   if (url == instant_url)
     return;
 
   // Commit the navigation if either:
   //  - The page is in NTP mode (so it could only navigate on a user click) or
   //  - The page is not in NTP mode and we are navigating to a URL with a
   //    different host or path than the instant URL. This enables the instant
   //    page when it is showing search results to change the query parameters
   //    and fragments of the URL without it navigating.
@@ skipping 314 matching lines @@
   }
 
   std::map<std::string, int>::const_iterator iter =
       blacklisted_urls_.find(*instant_url);
   if (iter != blacklisted_urls_.end() &&
       iter->second > kMaxInstantSupportFailures)
     return false;
 
   return true;
 }