Consistently use LoFi for an entire page

chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc

Index: chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
diff --git a/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc b/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
index aa4705e9c628f7ffdb6ba3162844bff8c2f5fb87..7e6279958ddca97f9b7832a917adc43406e3442a 100644
--- a/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
+++ b/chrome/browser/renderer_host/chrome_resource_dispatcher_host_delegate.cc
@@ -34,6 +34,7 @@
 #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"
@@ -738,6 +739,20 @@ void ChromeResourceDispatcherHostDelegate::RequestComplete(
   }
 }
 
+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(