Add Data Saver support to Cronet

components/cronet/android/cronet_data_reduction_proxy.cc

Index: components/cronet/android/cronet_data_reduction_proxy.cc
diff --git a/components/cronet/android/cronet_data_reduction_proxy.cc b/components/cronet/android/cronet_data_reduction_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..beed46c06e1787a448355f905beb70152835bfce
--- /dev/null
+++ b/components/cronet/android/cronet_data_reduction_proxy.cc
@@ -0,0 +1,99 @@
+// Copyright 2015 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 "components/cronet/android/cronet_data_reduction_proxy.h"
+
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/pref_service.h"
+#include "base/prefs/pref_service_factory.h"
+#include "base/single_thread_task_runner.h"
+#include "components/cronet/android/cronet_pref_store.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_service.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_statistics_prefs.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
+#include "net/base/net_log.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_interceptor.h"
+
+namespace {
+// Shows notifications which correspond to PersistentPrefStore's reading errors.
+void HandleReadError(PersistentPrefStore::PrefReadError error) {
+}
+}  // namespace
+
+namespace cronet {
+
+// static
+scoped_ptr<PrefService>
+CronetDataReductionProxy::CreatePrefService() {
+  PrefRegistrySimple* pref_registry = new PrefRegistrySimple();
+  data_reduction_proxy::RegisterSimpleProfilePrefs(pref_registry);
+  base::PrefServiceFactory pref_service_factory;
+  pref_service_factory.set_user_prefs(
+      make_scoped_refptr(new CronetPrefStore()));
+  pref_service_factory.set_read_error_callback(base::Bind(&HandleReadError));
+  return pref_service_factory.Create(pref_registry).Pass();
+}
+
+CronetDataReductionProxy::CronetDataReductionProxy(
+    const std::string& key,
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner,
+    net::NetLog* net_log)
+    : task_runner_(task_runner) {
+  prefs_ = CreatePrefService();
+  settings_.reset(
+      new data_reduction_proxy::DataReductionProxySettings());
+  io_data_.reset(
+      new data_reduction_proxy::DataReductionProxyIOData(
+          data_reduction_proxy::Client::CRONET_ANDROID,
+          data_reduction_proxy::DataReductionProxyParams::kAllowed |
+              data_reduction_proxy::DataReductionProxyParams::kFallbackAllowed,
+          net_log, task_runner, task_runner, false));
+  io_data_->request_options()->SetKeyOnIO(key);
+}
+
+CronetDataReductionProxy::~CronetDataReductionProxy() {
+  io_data_->ShutdownOnUIThread();
+}
+
+net::NetworkDelegate* CronetDataReductionProxy::CreateNetworkDelegate(
+    scoped_ptr<net::NetworkDelegate> wrapped_network_delegate) {
+  return io_data_->CreateNetworkDelegate(
+          wrapped_network_delegate.Pass(),
+          false /* No UMA is produced to track bypasses*/ ).release();
+}
+
+scoped_ptr<net::URLRequestInterceptor>
+CronetDataReductionProxy::CreateInterceptor() {
+  return io_data_->CreateInterceptor();
+}
+
+void CronetDataReductionProxy::Init(bool enable,
+                                    net::URLRequestContext* context) {
+  url_request_context_getter_ =
+      new net::TrivialURLRequestContextGetter(
+          context, task_runner_);
+  base::TimeDelta commit_delay = base::TimeDelta();

[mmenke, 2015/03/13 18:16:47]

explicit initialization not needed.  Suggest just inlining base::TimeDelta() and
getting rid of the variable.

[bengr, 2015/03/19 01:03:50]

Done.

+  scoped_ptr<data_reduction_proxy::DataReductionProxyStatisticsPrefs>
+      statistics_prefs = make_scoped_ptr(

[mmenke, 2015/03/13 18:16:47]

"make_scoped_ptr(" not needed.  Can just use

scoped_ptr<...> statistics_pref(new ...);

[bengr, 2015/03/19 01:03:50]

I thought make_scoped pointer was just shorthand for your suggestion because of
this comment:
https://code.google.com/p/chromium/codesearch#chromium/src/base/memory/scoped...

Am I missing something?

[mmenke, 2015/03/19 02:50:17]

You're missing that the "shorthand" is longer in this case.

scoped_ptr<Blah> blah(new Blah)
is shorter than:
scoped_ptr<Blah> blah = make_scoped_ptr(new Blah)

it's useful when passing in a scoped_ptr to a method:
Foo(make_scoped_ptr(new Blah))
is nicer than:
Foo(scoped_ptr(new Blah).Pass())

At least I believe that's what it's for (The pass may no longer be needed in the
second line, but I think it used to be?)

[bengr, 2015/03/19 17:56:24]

Oh. I misread my own code. Yes, of course. I completely agree. Done.

+          new data_reduction_proxy::DataReductionProxyStatisticsPrefs(
+              prefs_.get(), task_runner_, commit_delay));
+  scoped_ptr<data_reduction_proxy::DataReductionProxyService>
+      data_reduction_proxy_service(
+          new data_reduction_proxy::DataReductionProxyService(
+              statistics_prefs.Pass(), settings_.get(),
+              url_request_context_getter_.get()));
+  io_data_->SetDataReductionProxyService(
+      data_reduction_proxy_service->GetWeakPtr());
+  settings_->InitDataReductionProxySettings(
+      prefs_.get(), io_data_.get(), data_reduction_proxy_service.Pass());
+  settings_->SetDataReductionProxyEnabled(enable);
+}
+
+}  // namespace cronet