Introduce dynamic ablation of AutocompleteProviders using AC dynamic trials.

chrome/browser/autocomplete/autocomplete_controller.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/autocomplete/autocomplete_controller.h"
 
 #include <set>
 #include <string>
 
 #include "base/command_line.h"
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time.h"
 #include "chrome/browser/autocomplete/autocomplete_controller_delegate.h"
+#include "chrome/browser/autocomplete/autocomplete_field_trial.h"
 #include "chrome/browser/autocomplete/bookmark_provider.h"
 #include "chrome/browser/autocomplete/builtin_provider.h"
 #include "chrome/browser/autocomplete/extension_app_provider.h"
 #include "chrome/browser/autocomplete/history_contents_provider.h"
 #include "chrome/browser/autocomplete/history_quick_provider.h"
 #include "chrome/browser/autocomplete/history_url_provider.h"
 #include "chrome/browser/autocomplete/keyword_provider.h"
 #include "chrome/browser/autocomplete/search_provider.h"
 #include "chrome/browser/autocomplete/shortcuts_provider.h"
 #include "chrome/browser/autocomplete/zero_suggest_provider.h"
@@ skipping 59 matching lines @@
     AutocompleteControllerDelegate* delegate,
     int provider_types)
     : delegate_(delegate),
       keyword_provider_(NULL),
       search_provider_(NULL),
       zero_suggest_provider_(NULL),
       done_(true),
       in_start_(false),
       in_zero_suggest_(false),
       profile_(profile) {
+  // AND with the disabled providers, if any.
+  provider_types &= ~AutocompleteFieldTrial::GetDisabledProviderTypes();
   bool use_hqp = !!(provider_types & AutocompleteProvider::TYPE_HISTORY_QUICK);
   // TODO(mrossetti): Permanently modify the HistoryURLProvider to not search
   // titles once HQP is turned on permanently.
   // History quick provider can be used on all platforms other than Android.
   // TODO(jcivelli): Enable the History Quick Provider and figure out why it
   // reports the wrong results for some pages.
 #if defined(OS_ANDROID)
   use_hqp = false;
 #endif
 
@@ skipping 415 matching lines @@
   }
   done_ = true;
 }
 
 void AutocompleteController::StartExpireTimer() {
   if (result_.HasCopiedMatches())
     expire_timer_.Start(FROM_HERE,
                         base::TimeDelta::FromMilliseconds(kExpireTimeMS),
                         this, &AutocompleteController::ExpireCopiedEntries);
 }