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

chrome/browser/search/search.h

 // 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.
 
 #ifndef CHROME_BROWSER_SEARCH_SEARCH_H_
 #define CHROME_BROWSER_SEARCH_SEARCH_H_
 
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 103 matching lines @@
 // been extracted. Failing that, it tries to extract search terms from the URL.
 //
 // Returns a blank string if search terms were not found, or if search terms
 // extraction is disabled for this WebContents or profile, or if |contents|
 // does not support Instant.
 base::string16 GetSearchTerms(const content::WebContents* contents);
 
 // Returns true if |url| should be rendered in the Instant renderer process.
 bool ShouldAssignURLToInstantRenderer(const GURL& url, Profile* profile);
 
+// Returns true if |contents| is rendered inside the Instant process for
+// |profile|.
+bool IsRenderedInInstantProcess(const content::WebContents* contents,
+                                Profile* profile);
+
 // Returns true if the Instant |url| should use process per site.
 bool ShouldUseProcessPerSiteForInstantURL(const GURL& url, Profile* profile);
 
 // Returns true if |url| corresponds to a New Tab page (it can be either an
 // Instant Extended NTP or a non-extended NTP).
 bool IsNTPURL(const GURL& url, Profile* profile);
 
 // Returns true if the visible entry of |contents| is a New Tab Page rendered
 // by Instant. A page that matches the search or Instant URL of the default
 // search provider but does not have any search terms is considered an Instant
@@ skipping 151 matching lines @@
 bool GetBoolValueForFlagWithDefault(const std::string& flag,
                                     bool default_value,
                                     const FieldTrialFlags& flags);
 
 // Returns the Cacheable New Tab Page URL for the given |profile|.
 GURL GetNewTabPageURL(Profile* profile);
 
 }  // namespace chrome
 
 #endif  // CHROME_BROWSER_SEARCH_SEARCH_H_