InstantExtended: Bail on TemplateURLs with no espv.

chrome/browser/ui/search/search.cc

 // Copyright (c) 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/ui/search/search.h"
 
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/string_number_conversions.h"
 #include "base/string_split.h"
 #include "base/string_util.h"
 #include "chrome/browser/profiles/profile.h"
+#include "chrome/browser/search_engines/template_url_service.h"
+#include "chrome/browser/search_engines/template_url_service_factory.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
+#include "googleurl/src/gurl.h"
 
 #if !defined(OS_ANDROID)
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #endif
 
 namespace chrome {
 namespace search {
+namespace {
+// Returns whether |template_url| supports the parameter necessary to enable
+// InstantExtended.
+bool SupportsInstantExtended(const TemplateURL* template_url) {
+  if (!template_url)
+    return false;
+  const TemplateURLRef& instant_url_ref = template_url->instant_url_ref();
+  if (!instant_url_ref.IsValid())
+    return false;
+  const std::string search_url = instant_url_ref.ReplaceSearchTerms(
+      TemplateURLRef::SearchTermsArgs(string16()));
+  return template_url->HasSearchTermsReplacementKey(GURL(search_url));

[beaudoin, 2013/01/16 14:52:27]

Couldn't we assume that any TemplateURL that has a non-empty
search_terms_replacement_key support instant extended? Looking that the
instant_url_ref actually contains the search_terms_replacement key looks like a
DCHECK (since it's essentially hardcoded, coming from
prepopulated_engines.json).
Or is my assumption wrong and this "pinning" you talk about can occur on the
instant_url_ref but not in the other TemplateURL fields?

[Jered, 2013/01/16 21:27:04]

Oops sorry missed this. Your assumption was correct (though the new approach
avoids this).

+}
+}  // namespace
 
 // Configuration options for Embedded Search.
 // InstantExtended field trials are named in such a way that we can parse out
 // the experiment configuration from the trial's group name in order to give
 // us maximum flexability in running experiments.
 // Field trials should be named things like "Group7 espv:2 themes:0".
 // The first token is always GroupN for some integer N, followed by a
 // space-delimited list of key:value pairs which correspond to these flags:
 const char kEnableOnThemesFlagName[] = "themes";
 const bool kEnableOnThemesDefault = false;
@@ skipping 74 matching lines @@
 // Determine what embedded search page version to request from the user's
 // default search provider.  If 0, the embedded search UI should not be enabled.
 // Note that the profile object here isn't const because we need to determine
 // whether or not the user has a theme installed as part of this check, and
 // that logic requires a non-const profile for whatever reason.
 uint64 EmbeddedSearchPageVersion(Profile* profile) {
   // Incognito windows do not currently use the embedded search API.
   if (!profile || profile->IsOffTheRecord())
     return 0;
 
+  // Some users may have their search provider TemplateURL pinned to an
+  // obsolete value which does not support enabling InstantExtended on the
+  // server side. Bail out of InstantExtended if we detect that.
+  const TemplateURL* template_url =
+      TemplateURLServiceFactory::GetForProfile(profile)->
+      GetDefaultSearchProvider();
+  if (!SupportsInstantExtended(template_url))
+    return 0;
+
   // Check Finch field trials.
   FieldTrialFlags flags;
   uint64 group_number = 0;
   base::FieldTrial* trial =
       base::FieldTrialList::Find(kInstantExtendedFieldTrialName);
   if (trial) {
     std::string group_name = trial->group_name();
     GetFieldTrialInfo(group_name, &flags, &group_number);
   }
 
@@ skipping 17 matching lines @@
     if (!has_theme || enable_for_themes)
       return espv;
   }
 
   if (CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableInstantExtendedAPI)) {
     // The user has manually flipped the about:flags switch - give the default
     // UI version.
     return kEmbeddedPageVersionDefault;
   }
+
   return 0;
 }
 
 void EnableInstantExtendedAPIForTesting() {
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kEnableInstantExtendedAPI);
 }
 
 bool IsQueryExtractionEnabled(Profile* profile) {
 #if defined(OS_IOS)
@@ skipping 20 matching lines @@
 #else
   // On desktop, query extraction is controlled by the instant-extended-api
   // flag.
   CommandLine::ForCurrentProcess()->AppendSwitch(
       switches::kEnableInstantExtendedAPI);
 #endif
 }
 
 }  // namespace search
 }  // namespace chrome