Consistently use LoFi for an entire page

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.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/renderer_host/chrome_resource_dispatcher_host_delegate.h"
 
 #include <string>
 #include <vector>
 
 #include "base/base64.h"
@@ skipping 16 matching lines @@
 #include "chrome/browser/profiles/profile_io_data.h"
 #include "chrome/browser/renderer_host/data_reduction_proxy_resource_throttle_android.h"
 #include "chrome/browser/renderer_host/safe_browsing_resource_throttle.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
 #include "chrome/browser/signin/chrome_signin_helper.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "chrome/browser/ui/login/login_prompt.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/google/core/browser/google_util.h"
 #include "components/variations/net/variations_http_header_provider.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/plugin_service.h"
 #include "content/public/browser/plugin_service_filter.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/resource_context.h"
 #include "content/public/browser/resource_dispatcher_host.h"
@@ skipping 684 matching lines @@
   if (url_request && !url_request->was_cached()) {
     BrowserThread::PostTask(BrowserThread::UI,
                             FROM_HERE,
                             base::Bind(&UpdatePrerenderNetworkBytesCallback,
                                        info->GetChildID(),
                                        info->GetRouteID(),
                                        url_request->GetTotalReceivedBytes()));
   }
 }
 
+bool ChromeResourceDispatcherHostDelegate::ShouldEnableLoFiMode(
+    net::URLRequest* url_request,
+    content::ResourceContext* resource_context) {
+  ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
+  data_reduction_proxy::DataReductionProxyIOData* data_reduction_proxy_io_data =
+      io_data->data_reduction_proxy_io_data();

[mmenke, 2015/09/29 16:35:57]

Why does this need to go through a new DRP class?

If we want field trials to enable lofi mode only when using the DRP, I'd suggest
putting that logic here (Setting a bool based on the trial on creation of this
class, and checking if the DRP is enabled / will be used for the request here),
rather than adding a separate class just for this one experiment.

Or is there something I'm missing?

[megjablon, 2015/09/29 21:20:07]

This isn't a new class. This is just adding a method to an existing class.
ShouldEnableLoFiMode doesn't simply check the field trials and the DRP being
enabled, it asks the network quality estimator if Lo-Fi should be enabled based
on the connection.

+
+  if (url_request && data_reduction_proxy_io_data) {

[mmenke, 2015/09/29 16:35:57]

url_request can't be NULL, so shouldn't check for it.

[megjablon, 2015/09/29 21:20:07]

Done.

+    return data_reduction_proxy_io_data->ShouldEnableLoFiMode(url_request);
+  }

[mmenke, 2015/09/29 16:35:57]

nit:  Remove braces.

[megjablon, 2015/09/29 21:20:06]

Done.

+
+  return false;
+}
+
 // static
 void ChromeResourceDispatcherHostDelegate::
     SetExternalProtocolHandlerDelegateForTesting(
     ExternalProtocolHandler::Delegate* delegate) {
   g_external_protocol_handler_delegate = delegate;
 }