Exempt Save-Data header from CORS preflight request check

chrome/browser/chrome_content_browser_client.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/chrome_content_browser_client.h"
 
 #include <map>
 #include <set>
 #include <utility>
 #include <vector>
@@ skipping 677 matching lines @@
     NOTREACHED();
     return;
   }
 
   UsbTabHelper* tab_helper =
       UsbTabHelper::GetOrCreateForWebContents(web_contents);
   tab_helper->CreatePermissionBubble(render_frame_host, std::move(request));
 }
 #endif  // !defined(OS_ANDROID) && !defined(OS_IOS)
 
+bool GetDataSaverEnabledPref(const PrefService* prefs) {
+  // Enable data saver only when data saver pref is enabled and not part of
+  // "Disabled" group of "SaveDataHeader" experiment.
+  return prefs->GetBoolean(prefs::kDataSaverEnabled) &&
+         base::FieldTrialList::FindFullName("SaveDataHeader")
+             .compare("Disabled");
+}
+
 }  // namespace
 
 ChromeContentBrowserClient::ChromeContentBrowserClient()
     :
       weak_factory_(this) {
 #if defined(ENABLE_PLUGINS)
   for (size_t i = 0; i < arraysize(kPredefinedAllowedDevChannelOrigins); ++i)
     allowed_dev_channel_origins_.insert(kPredefinedAllowedDevChannelOrigins[i]);
   for (size_t i = 0; i < arraysize(kPredefinedAllowedFileHandleOrigins); ++i)
     allowed_file_handle_origins_.insert(kPredefinedAllowedFileHandleOrigins[i]);
@@ skipping 1664 matching lines @@
   }
   DCHECK(!web_prefs->default_encoding.empty());
 
   if (base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnablePotentiallyAnnoyingSecurityFeatures)) {
     web_prefs->disable_reading_from_canvas = true;
     web_prefs->strict_mixed_content_checking = true;
     web_prefs->strict_powerful_feature_restrictions = true;
   }
 
-  web_prefs->data_saver_enabled =
-      prefs->GetBoolean(prefs::kDataSaverEnabled);
+  web_prefs->data_saver_enabled = GetDataSaverEnabledPref(prefs);
 
   for (size_t i = 0; i < extra_parts_.size(); ++i)
     extra_parts_[i]->OverrideWebkitPrefs(rvh, web_prefs);
 }
 
 void ChromeContentBrowserClient::BrowserURLHandlerCreated(
     BrowserURLHandler* handler) {
   for (size_t i = 0; i < extra_parts_.size(); ++i)
     extra_parts_[i]->BrowserURLHandlerCreated(handler);
 
@@ skipping 506 matching lines @@
   if (channel <= kMaxDisableEncryptionChannel) {
     static const char* const kWebRtcDevSwitchNames[] = {
       switches::kDisableWebRtcEncryption,
     };
     to_command_line->CopySwitchesFrom(from_command_line,
                                       kWebRtcDevSwitchNames,
                                       arraysize(kWebRtcDevSwitchNames));
   }
 }
 #endif  // defined(ENABLE_WEBRTC)