Discard ChromeViewHostMsg_SearchBox* IPCs if they not sent from an Instant process.

chrome/browser/ui/search/search_ipc_router.cc

 // Copyright 2013 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/ui/search/search_ipc_router.h"
 
+#include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/search/search.h"
 #include "chrome/common/render_messages.h"
 #include "content/public/browser/navigation_details.h"
 #include "content/public/browser/web_contents.h"
 
 namespace {
 
 bool IsProviderValid(const base::string16& provider) {
   // Only allow string of 8 alphanumeric characters or less as providers.
   // The empty string is considered valid and should be treated as if no
@@ skipping 126 matching lines @@
 
 void SearchIPCRouter::OnTabActivated() {
   is_active_tab_ = true;
 }
 
 void SearchIPCRouter::OnTabDeactivated() {
   is_active_tab_ = false;
 }
 
 bool SearchIPCRouter::OnMessageReceived(const IPC::Message& message) {
+  Profile* profile =
+      Profile::FromBrowserContext(web_contents()->GetBrowserContext());
+  if (!chrome::IsRenderedInInstantProcess(web_contents(), profile))
+    return false;
+
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(SearchIPCRouter, message)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_InstantSupportDetermined,
                         OnInstantSupportDetermined)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SetVoiceSearchSupported,
                         OnVoiceSearchSupportDetermined)
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_FocusOmnibox, OnFocusOmnibox);
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SearchBoxNavigate,
                         OnSearchBoxNavigate);
     IPC_MESSAGE_HANDLER(ChromeViewHostMsg_SearchBoxDeleteMostVisitedItem,
@@ skipping 164 matching lines @@
 
 void SearchIPCRouter::set_delegate_for_testing(Delegate* delegate) {
   DCHECK(delegate);
   delegate_ = delegate;
 }
 
 void SearchIPCRouter::set_policy_for_testing(scoped_ptr<Policy> policy) {
   DCHECK(policy.get());
   policy_.reset(policy.release());
 }