InstantExtended: add a finch flag to disable Instant Extended on SRP.

chrome/browser/search/search.cc

Index: chrome/browser/search/search.cc
diff --git a/chrome/browser/search/search.cc b/chrome/browser/search/search.cc
index de725fb1938d464e478e1fc21ad65700beb0032e..1dcc72fdc5c0810c34f74afc233d53ddccadca95 100644
--- a/chrome/browser/search/search.cc
+++ b/chrome/browser/search/search.cc
@@ -64,6 +64,7 @@ const char kShowNtpFlagName[] = "show_ntp";
 const char kRecentTabsOnNTPFlagName[] = "show_recent_tabs";
 const char kUseCacheableNTP[] = "use_cacheable_ntp";
 const char kPrefetchSearchResultsOnSRP[] = "prefetch_results_srp";
+const char kSuppressInstantExtendedOnSRPFlagName[] = "suppress_on_srp";
 
 // Constants for the field trial name and group prefix.
 const char kInstantExtendedFieldTrialName[] = "InstantExtended";
@@ -230,9 +231,14 @@ bool IsInstantURL(const GURL& url, Profile* profile) {
   const TemplateURLRef& instant_url_ref = template_url->instant_url_ref();
   const GURL instant_url =
       TemplateURLRefToGURL(instant_url_ref, kDisableStartMargin, false);
-  return instant_url.is_valid() &&
-      (MatchesOriginAndPath(url, instant_url) ||
-       MatchesAnySearchURL(url, template_url));
+  if (!instant_url.is_valid())
+    return false;
+
+  if (MatchesOriginAndPath(url, instant_url))
+    return true;
+
+  return !ShouldSuppressInstantExtendedOnSRP() &&
+      MatchesAnySearchURL(url, template_url);
 }
 
 string16 GetSearchTermsImpl(const content::WebContents* contents,
@@ -273,10 +279,8 @@ bool IsInstantExtendedAPIEnabled() {
 #if defined(OS_IOS) || defined(OS_ANDROID)
   return false;
 #else
-  // On desktop, query extraction is part of Instant extended, so if one is
-  // enabled, the other is too.
   RecordInstantExtendedOptInState();
-  return IsQueryExtractionEnabled();
+  return EmbeddedSearchPageVersion() != kEmbeddedPageVersionDisabled;
 #endif  // defined(OS_IOS) || defined(OS_ANDROID)
 }
 
@@ -311,7 +315,8 @@ uint64 EmbeddedSearchPageVersion() {
 }
 
 bool IsQueryExtractionEnabled() {
-  return EmbeddedSearchPageVersion() != kEmbeddedPageVersionDisabled;
+  return EmbeddedSearchPageVersion() != kEmbeddedPageVersionDisabled &&
+      !ShouldSuppressInstantExtendedOnSRP();
 }
 
 string16 GetSearchTermsFromURL(Profile* profile, const GURL& url) {
@@ -508,6 +513,18 @@ bool ShouldShowRecentTabsOnNTP() {
   return false;
 }
 
+bool ShouldSuppressInstantExtendedOnSRP() {
+  FieldTrialFlags flags;
+  if (GetFieldTrialInfo(
+          base::FieldTrialList::FindFullName(kInstantExtendedFieldTrialName),
+          &flags, NULL)) {
+    return GetBoolValueForFlagWithDefault(
+        kSuppressInstantExtendedOnSRPFlagName, false, flags);
+  }
+
+  return false;
+}
+
 bool MatchesOriginAndPath(const GURL& my_url, const GURL& other_url) {
   return MatchesOrigin(my_url, other_url) && my_url.path() == other_url.path();
 }