Add Data Saver support to Cronet

components/cronet/android/cronet_url_request_context_adapter.cc

Index: components/cronet/android/cronet_url_request_context_adapter.cc
diff --git a/components/cronet/android/cronet_url_request_context_adapter.cc b/components/cronet/android/cronet_url_request_context_adapter.cc
index 39c585a84423e79b81ea0c700d5bc9536c7ff90f..6609246a620d8b2c8a438603ea4c66b9d7d00f0c 100644
--- a/components/cronet/android/cronet_url_request_context_adapter.cc
+++ b/components/cronet/android/cronet_url_request_context_adapter.cc
@@ -7,10 +7,12 @@
 #include "base/android/jni_android.h"
 #include "base/android/jni_string.h"
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "base/values.h"
+#include "components/cronet/android/cronet_data_reduction_proxy.h"
 #include "components/cronet/url_request_context_config.h"
 #include "jni/CronetUrlRequestContext_jni.h"
 #include "net/base/load_flags.h"
@@ -22,6 +24,7 @@
 #include "net/proxy/proxy_service.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_builder.h"
+#include "net/url_request/url_request_interceptor.h"
 
 namespace {
 
@@ -132,8 +135,7 @@ void CronetURLRequestContextAdapter::InitRequestContextOnMainThread(
     jobject jcaller) {
   base::android::ScopedJavaGlobalRef<jobject> jcaller_ref;
   jcaller_ref.Reset(env, jcaller);
-  proxy_config_service_.reset(net::ProxyService::CreateSystemProxyConfigService(
-      GetNetworkTaskRunner(), nullptr));

[mmenke, 2015/03/13 18:16:48]

Think a CL to fix this has already landed, make sure you've merged (Shouldn't
affect your CL at all, just one fewer steps once you get a signoff)

[bengr, 2015/03/19 01:03:51]

Acknowledged, though I didn't see a fix yet.

+  base::CommandLine::Init(0, nullptr);

[mmenke, 2015/03/13 18:16:48]

Hrm...Wonder if we should move command line checking out of the component (I may
have been the one that suggested moving it out, though, come to think of it). 
Anyhow, I think this is fine for now, but this call should probably be in
cronet_library_loader.cc.

[bengr, 2015/03/19 01:03:51]

Done.

   GetNetworkTaskRunner()->PostTask(
       FROM_HERE,
       base::Bind(&CronetURLRequestContextAdapter::InitializeOnNetworkThread,
@@ -147,13 +149,33 @@ void CronetURLRequestContextAdapter::InitializeOnNetworkThread(
         jcronet_url_request_context) {
   DCHECK(GetNetworkTaskRunner()->BelongsToCurrentThread());
   DCHECK(!is_context_initialized_);
+  scoped_ptr<net::NetLog> net_log(new net::NetLog);
+  DCHECK(!data_reduction_proxy_);
+  // For now, the choice to enable the data reduction proxy happens once,
+  // at initialization. It cannot be disabled thereafter.
+  if (config->enable_data_reduction_proxy) {
+  data_reduction_proxy_.reset(new CronetDataReductionProxy(
+      config->data_reduction_proxy_key, GetNetworkTaskRunner(), net_log.get()));
+  }

[mmenke, 2015/03/13 18:16:48]

Can we just merge this with the "if (DRP)" block below?

[bengr, 2015/03/19 01:03:51]

Done.

   // TODO(mmenke):  Add method to have the builder enable SPDY.
   net::URLRequestContextBuilder context_builder;
-  context_builder.set_network_delegate(new BasicNetworkDelegate());
-  context_builder.set_proxy_config_service(
-      new net::ProxyConfigServiceFixed(net::ProxyConfig()));
+  if (data_reduction_proxy_) {
+    context_builder.set_network_delegate(
+        data_reduction_proxy_->CreateNetworkDelegate(
+            make_scoped_ptr(new BasicNetworkDelegate())));
+    net::URLRequestContextBuilder::URLRequestInterceptors interceptors;
+    interceptors.push_back(data_reduction_proxy_->CreateInterceptor());
+    context_builder.SetInterceptors(interceptors.Pass());
+  } else {
+    context_builder.set_network_delegate(new BasicNetworkDelegate());
+  }
+  context_builder.set_proxy_service(
+      net::ProxyService::CreateWithoutProxyResolver(
+          net::ProxyService::CreateSystemProxyConfigService(
+              GetNetworkTaskRunner(), nullptr),
+          net_log.get()));
   config->ConfigureURLRequestContextBuilder(&context_builder);
-
+  context_builder.set_net_log(net_log.release());
   context_.reset(context_builder.Build());
 
   default_load_flags_ = net::LOAD_DO_NOT_SAVE_COOKIES |
@@ -214,6 +236,9 @@ void CronetURLRequestContextAdapter::InitializeOnNetworkThread(
     tasks_waiting_for_context_.front().Run();
     tasks_waiting_for_context_.pop();
   }
+  if (data_reduction_proxy_)
+    data_reduction_proxy_->Init(config->enable_data_reduction_proxy,
+                                GetURLRequestContext());

[mmenke, 2015/03/13 18:16:48]

nit:  Use braces.

[bengr, 2015/03/19 01:03:51]

Done.

 }
 
 void CronetURLRequestContextAdapter::Destroy(JNIEnv* env, jobject jcaller) {