Fetch a warmup URL if data reduction proxy is enabled

components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
index 385bf60ea791135f7f7426cd445cee62bb791149..6b115a3ce23dfab56a92e3db07dd01586d4806a1 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h
@@ -51,6 +51,7 @@ class DataReductionProxyConfigValues;
 class DataReductionProxyConfigurator;
 class DataReductionProxyEventCreator;
 class SecureProxyChecker;
+class WarmupURLFetcher;
 struct DataReductionProxyTypeInfo;
 
 // Values of the UMA DataReductionProxy.ProbeURL histogram.
@@ -103,8 +104,13 @@ class DataReductionProxyConfig
   ~DataReductionProxyConfig() override;
 
   // Performs initialization on the IO thread.
-  void InitializeOnIOThread(const scoped_refptr<net::URLRequestContextGetter>&
-                                url_request_context_getter);
+  // |basic_url_request_context_getter| is the net::URLRequestContextGetter that
+  // disables the use of alternative protocols. |url_request_context_getter| is

[RyanSturm, 2016/12/08 20:59:17]

nit: s/alternative protocols/alternative protocols and proxies/

[tbansal1, 2016/12/10 00:48:49]

Done.

+  // the default net::URLRequestContextGetter used for making URL requests.
+  void InitializeOnIOThread(
+      const scoped_refptr<net::URLRequestContextGetter>&
+          basic_url_request_context_getter,
+      net::URLRequestContextGetter* url_request_context_getter);
 
   // Sets the proxy configs, enabling or disabling the proxy according to
   // the value of |enabled|. If |restricted| is true, only enable the fallback
@@ -214,6 +220,10 @@ class DataReductionProxyConfig
   // Updates the Data Reduction Proxy configurator with the current config.
   void UpdateConfigForTesting(bool enabled, bool restricted);
 
+  // Updates the callback called when the warm up URL has been fetched.

[RyanSturm, 2016/12/08 20:59:17]

s/callback called/callback that is called/

[tbansal1, 2016/12/10 00:48:49]

Done.

+  void SetWarmupURLFetcherCallbackForTesting(
+      base::Callback<void()> warmup_url_fetched_callback);
+
  private:
   friend class MockDataReductionProxyConfig;
   friend class TestDataReductionProxyConfig;
@@ -230,6 +240,7 @@ class DataReductionProxyConfig
   FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest, LoFiAccuracy);
   FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest,
                            LoFiAccuracyNonZeroDelay);
+  FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigTest, WarmupURL);
 
   // Values of the estimated network quality at the beginning of the most
   // recent query of the Network Quality Estimator.
@@ -308,8 +319,13 @@ class DataReductionProxyConfig
   // for testing.
   virtual bool GetIsCaptivePortal() const;
 
+  // Fetches the warm up URL.
+  void FetchWarmupURL();
+
   std::unique_ptr<SecureProxyChecker> secure_proxy_checker_;
 
+  std::unique_ptr<WarmupURLFetcher> warmup_url_fetcher_;

[RyanSturm, 2016/12/08 20:59:17]

member comment for warmup_url_fetcher_. And for secure_proxy_checker_ if you
feel like it.

[tbansal1, 2016/12/10 00:48:49]

Done.

+
   // Indicates if the secure Data Reduction Proxy can be used or not.
   bool secure_proxy_allowed_;