[DRP] Consistently use LoFi for an entire page

components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
index 7598a203dce9fcebdbbb5b6d58c9a808ca96d97f..47c6627fa3ea4653caec5afb25ce183182870433 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
@@ -16,6 +16,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_event_creator.h"
+#include "components/data_reduction_proxy/core/common/lofi_decider.h"
 #include "net/base/load_flags.h"
 #include "net/http/http_response_headers.h"
 #include "net/proxy/proxy_info.h"
@@ -27,8 +28,6 @@
 
 namespace {
 
-class NetworkQualityEstimator;
-
 // |lofi_low_header_added| is set to true iff Lo-Fi "q=low" request header can
 // be added to the Chrome proxy headers.
 // |received_content_length| is the number of prefilter bytes received.
@@ -174,26 +173,23 @@ void DataReductionProxyNetworkDelegate::OnBeforeSendProxyHeadersInternal(
     const net::ProxyInfo& proxy_info,
     net::HttpRequestHeaders* headers) {
   DCHECK(data_reduction_proxy_config_);
+  bool is_using_lofi_mode = false;
+
+  if (data_reduction_proxy_io_data_ &&
+      data_reduction_proxy_io_data_->lofi_decider() && request) {
+    LoFiDecider* lofi_decider = data_reduction_proxy_io_data_->lofi_decider();
+    is_using_lofi_mode = lofi_decider->IsUsingLoFiMode(*request);

[bengr, 2015/10/16 21:10:07]

I don't understand how this is safe. What happens if
data_reduction_proxy_io_data_->lofi_decider() returns nullptr? The
is_using_lofi_mode = nullptr->IsUsingLoFiMode. Crash.

[megjablon, 2015/10/16 22:06:40]

On line 179 we check data_reduction_proxy_io_data_->lofi_decider()

[bengr, 2015/10/17 00:06:34]

Totally missed that. You could move assignment to lofi_decider before the "if"
statement. Not required.

[megjablon, 2015/10/19 19:44:21]

Done.

 
-  // TODO(bengr): Investigate a better approach to update the network
-  // quality so that state of Lo-Fi is stored per page.
-  net::NetworkQualityEstimator* network_quality_estimator = nullptr;
-  if (request && request->context())
-    network_quality_estimator = request->context()->network_quality_estimator();
-
-  if (request && ((request->load_flags() & net::LOAD_MAIN_FRAME) != 0)) {
-    data_reduction_proxy_config_->UpdateLoFiStatusOnMainFrameRequest(
-        ((request->load_flags() & net::LOAD_BYPASS_CACHE) != 0),
-        network_quality_estimator);
-    if (data_reduction_proxy_io_data_) {
+    if ((request->load_flags() & net::LOAD_MAIN_FRAME) != 0) {
+      // TODO(megjablon): Need to switch to per page.
       data_reduction_proxy_io_data_->SetLoFiModeActiveOnMainFrame(
-          data_reduction_proxy_config_->ShouldUseLoFiHeaderForRequests());
+          is_using_lofi_mode);
     }
   }
 
   if (data_reduction_proxy_request_options_) {
     data_reduction_proxy_request_options_->MaybeAddRequestHeader(
-        request, proxy_info.proxy_server(), headers);
+        request, proxy_info.proxy_server(), headers, is_using_lofi_mode);
   }
 }
 
@@ -256,13 +252,13 @@ void DataReductionProxyNetworkDelegate::OnCompletedInternal(
 
     DCHECK(data_reduction_proxy_config_);
 
-    // TODO(bengr): Investigate a better approach to record the Lo-Fi
-    // histogram. State of Lo-Fi should be stored per page.
     RecordContentLengthHistograms(
         // |data_reduction_proxy_io_data_| can be NULL for Webview.
         data_reduction_proxy_io_data_ &&
             data_reduction_proxy_io_data_->IsEnabled() &&
-            data_reduction_proxy_config_->ShouldUseLoFiHeaderForRequests(),
+            data_reduction_proxy_io_data_->lofi_decider() &&
+            data_reduction_proxy_io_data_->lofi_decider()->IsUsingLoFiMode(
+                *request),
         received_content_length, original_content_length, freshness_lifetime);
     experiments_stats_->RecordBytes(request->request_time(), request_type,
                                     received_content_length,