Add core plumbing for Instant Extended work

chrome/browser/google/google_util.h

Index: chrome/browser/google/google_util.h
diff --git a/chrome/browser/google/google_util.h b/chrome/browser/google/google_util.h
index 3e6a0fc4c33b8a37272a0d2468be8167357fd2af..fffe2aea8e2b9080d06ddef90078c44d8b5a66ec 100644
--- a/chrome/browser/google/google_util.h
+++ b/chrome/browser/google/google_util.h
@@ -66,6 +66,9 @@ bool IsGoogleHostname(const std::string& host, SubdomainPermission permission);
 bool IsGoogleHomePageUrl(const std::string& url);
 // True if |url| represents a valid Google search URL.
 bool IsGoogleSearchUrl(const std::string& url);
+// True if |url| represents a valid Google search URL used by the Instant
+// Extended API.
+bool IsInstantExtendedAPIGoogleSearchUrl(const std::string& url);
 
 // True if a build is strictly organic, according to its brand code.
 bool IsOrganic(const std::string& brand);