Add ClientConfig proto, and JSON generation/parsing.

- Add the ClientConfig proto definition corresponding to the response
  coming from the service.
- Create a means of generating a pseudo response from the built in
  params and request options.
- Create a class to parse the JSON response.
- Add necessary helper classes for the ProxyScheme and time values
  coming from the service.

BUG=466753

Review URL: https://codereview.chromium.org/1017853003

Cr-Commit-Position: refs/heads/master@{#321931}

18 files changed, 1008 insertions, 50 deletions

diff --git a/components/data_reduction_proxy/core/browser/BUILD.gn b/components/data_reduction_proxy/core/browser/BUILD.gn
index 0bc2867..5790d4c 100644
--- a/components/data_reduction_proxy/core/browser/BUILD.gn
+++ b/components/data_reduction_proxy/core/browser/BUILD.gn
@@ -8,6 +8,8 @@ static_library("browser") {
     "data_reduction_proxy_bypass_protocol.h",
     "data_reduction_proxy_config.cc",
     "data_reduction_proxy_config.h",
+    "data_reduction_proxy_config_service_client.cc",
+    "data_reduction_proxy_config_service_client.h",
     "data_reduction_proxy_configurator.cc",
     "data_reduction_proxy_configurator.h",
     "data_reduction_proxy_debug_ui_service.h",
@@ -41,6 +43,7 @@ static_library("browser") {
     "//base",
     "//base:prefs",
     "//components/data_reduction_proxy/core/common",
+    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//components/pref_registry",
     "//crypto",
     "//net",
@@ -85,6 +88,7 @@ source_set("unit_tests") {
   testonly = true
   sources = [
     "data_reduction_proxy_bypass_protocol_unittest.cc",
+    "data_reduction_proxy_config_service_client_unittest.cc",
     "data_reduction_proxy_config_unittest.cc",
     "data_reduction_proxy_configurator_unittest.cc",
     "data_reduction_proxy_interceptor_unittest.cc",
@@ -105,6 +109,7 @@ source_set("unit_tests") {
     "//base:prefs_test_support",
     "//base/test:test_support",
     "//components/data_reduction_proxy/core/common:test_support",
+    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.cc
new file mode 100644
index 0000000..39a9481
--- /dev/null
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.cc
@@ -0,0 +1,39 @@
+// 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/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h"
+
+#include "base/json/json_writer.h"
+#include "base/logging.h"
+#include "base/values.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
+
+namespace data_reduction_proxy {
+
+DataReductionProxyConfigServiceClient::DataReductionProxyConfigServiceClient(
+    DataReductionProxyParams* params,
+    DataReductionProxyRequestOptions* request_options)
+    : params_(params),
+      request_options_(request_options) {
+  DCHECK(params);
+  DCHECK(request_options);
+}
+
+DataReductionProxyConfigServiceClient::
+    ~DataReductionProxyConfigServiceClient() {
+}
+
+std::string
+DataReductionProxyConfigServiceClient::ConstructStaticResponse() const {
+  std::string response;
+  scoped_ptr<base::DictionaryValue> values(new base::DictionaryValue());
+  params_->PopulateConfigResponse(values.get());
+  request_options_->PopulateConfigResponse(values.get());
+  base::JSONWriter::Write(values.get(), &response);
+
+  return response;
+}
+
+}  // namespace data_reduction_proxy
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h
new file mode 100644
index 0000000..648cee4
--- /dev/null
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h
@@ -0,0 +1,48 @@
+// 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.
+
+#ifndef COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_CONFIG_SERVICE_CLIENT_H_
+#define COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_CONFIG_SERVICE_CLIENT_H_
+
+#include <string>
+
+#include "base/gtest_prod_util.h"
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+
+namespace data_reduction_proxy {
+
+class DataReductionProxyParams;
+class DataReductionProxyRequestOptions;
+
+// Retrieves the Data Reduction Proxy configuration from a remote service. This
+// object lives on the IO thread.
+class DataReductionProxyConfigServiceClient {
+ public:
+  // The caller must ensure that all parameters remain alive for the lifetime of
+  // the |DataReductionProxyConfigClient|.
+  DataReductionProxyConfigServiceClient(
+      DataReductionProxyParams* params,
+      DataReductionProxyRequestOptions* request_options);
+
+  ~DataReductionProxyConfigServiceClient();
+
+ private:
+  FRIEND_TEST_ALL_PREFIXES(DataReductionProxyConfigClientTest,
+                           TestConstructStaticResponse);
+
+  // Constructs a synthetic response based on |params_|.
+  std::string ConstructStaticResponse() const;
+
+  // The caller must ensure that the |params_| outlives this instance.
+  DataReductionProxyParams* params_;
+
+  // The caller must ensure that the |request_options_| outlives this instance.
+  DataReductionProxyRequestOptions* request_options_;
+
+  DISALLOW_COPY_AND_ASSIGN(DataReductionProxyConfigServiceClient);
+};
+
+}  // namespace data_reduction_proxy
+#endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_CONFIG_SERVICE_CLIENT_H_
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc
new file mode 100644
index 0000000..6b44ceb
--- /dev/null
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client_unittest.cc
@@ -0,0 +1,52 @@
+// 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/data_reduction_proxy/core/browser/data_reduction_proxy_config_service_client.h"
+
+#include <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/values.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config_test_utils.h"
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params_test_utils.h"
+#include "components/data_reduction_proxy/proto/client_config.pb.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace data_reduction_proxy {
+
+class DataReductionProxyConfigClientTest : public testing::Test {
+ protected:
+  void SetUp() override {
+    test_context_ =
+        DataReductionProxyTestContext::Builder()
+            .WithParamsFlags(DataReductionProxyParams::kAllowed |
+                             DataReductionProxyParams::kFallbackAllowed |
+                             DataReductionProxyParams::kPromoAllowed)
+            .WithParamsDefinitions(TestDataReductionProxyParams::HAS_EVERYTHING)
+            .Build();
+  }
+
+  scoped_ptr<DataReductionProxyConfigServiceClient> BuildConfigClient() {
+    return make_scoped_ptr(new DataReductionProxyConfigServiceClient(
+        test_context_->config()->test_params(),
+        test_context_->io_data()->request_options()));
+  }
+
+ private:
+  scoped_ptr<DataReductionProxyTestContext> test_context_;
+};
+
+TEST_F(DataReductionProxyConfigClientTest, TestConstructStaticResponse) {
+  scoped_ptr<DataReductionProxyConfigServiceClient> config_client =
+      BuildConfigClient();
+  std::string config_data = config_client->ConstructStaticResponse();
+  ClientConfig config;
+  EXPECT_TRUE(config_parser::ParseClientConfig(config_data, &config));
+}
+
+}  // namespace data_reduction_proxy
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
index 985dfa5..675b05c 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.cc
@@ -13,8 +13,10 @@
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/time/time.h"
+#include "base/values.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h"
@@ -69,6 +71,29 @@ bool DataReductionProxyRequestOptions::IsKeySetOnCommandLine() {
       data_reduction_proxy::switches::kDataReductionProxyKey);
 }
 
+// static
+std::string DataReductionProxyRequestOptions::CreateLocalSessionKey(
+    const std::string& session,
+    const std::string& credentials) {
+  return base::StringPrintf("%s|%s", session.c_str(), credentials.c_str());
+}
+
+// static
+bool DataReductionProxyRequestOptions::ParseLocalSessionKey(
+    const std::string& session_key,
+    std::string* session,
+    std::string* credentials) {
+  std::vector<std::string> auth_values;
+  base::SplitString(session_key, '|', &auth_values);
+  if (auth_values.size() == 2) {
+    *session = auth_values[0];
+    *credentials = auth_values[1];
+    return true;
+  }
+
+  return false;
+}
+
 DataReductionProxyRequestOptions::DataReductionProxyRequestOptions(
     Client client,
     DataReductionProxyConfig* config,
@@ -172,7 +197,8 @@ base::Time DataReductionProxyRequestOptions::Now() const {
   return base::Time::Now();
 }
 
-void DataReductionProxyRequestOptions::RandBytes(void* output, size_t length) {
+void DataReductionProxyRequestOptions::RandBytes(void* output,
+                                                 size_t length) const {
   crypto::RandBytes(output, length);
 }
 
@@ -200,10 +226,9 @@ void DataReductionProxyRequestOptions::MaybeAddProxyTunnelRequestHandler(
 void DataReductionProxyRequestOptions::SetHeader(
     net::HttpRequestHeaders* headers) {
   base::Time now = Now();
-  // Authorization credentials must be regenerated at least every 24 hours.
-  if (now - last_credentials_update_time_ > base::TimeDelta::FromHours(24)) {
+  // Authorization credentials must be regenerated if they are expired.
+  if (now > credentials_expiration_time_)
     UpdateCredentials();
-  }
   UpdateLoFi();
   const char kChromeProxyHeader[] = "Chrome-Proxy";
   std::string header_value;
@@ -219,7 +244,7 @@ void DataReductionProxyRequestOptions::SetHeader(
 void DataReductionProxyRequestOptions::ComputeCredentials(
     const base::Time& now,
     std::string* session,
-    std::string* credentials) {
+    std::string* credentials) const {
   DCHECK(session);
   DCHECK(credentials);
   int64 timestamp =
@@ -241,8 +266,9 @@ void DataReductionProxyRequestOptions::ComputeCredentials(
 void DataReductionProxyRequestOptions::UpdateCredentials() {
   std::string session;
   std::string credentials;
-  last_credentials_update_time_ = Now();
-  ComputeCredentials(last_credentials_update_time_, &session_, &credentials_);
+  base::Time now = Now();
+  ComputeCredentials(now, &session_, &credentials_);
+  credentials_expiration_time_ = now + base::TimeDelta::FromHours(24);
   RegenerateRequestHeaderValue();
 }
 
@@ -253,6 +279,20 @@ void DataReductionProxyRequestOptions::SetKeyOnIO(const std::string& key) {
   }
 }
 
+void DataReductionProxyRequestOptions::PopulateConfigResponse(
+    base::DictionaryValue* response) const {
+  DCHECK(network_task_runner_->BelongsToCurrentThread());
+  std::string session;
+  std::string credentials;
+  base::Time now = Now();
+  base::Time expiration_time = now + base::TimeDelta::FromHours(24);
+  ComputeCredentials(now, &session, &credentials);
+  response->SetString("sessionKey",
+                      CreateLocalSessionKey(session, credentials));
+  response->SetString("expireTime",
+                      config_parser::TimeToISO8601(expiration_time));
+}
+
 std::string DataReductionProxyRequestOptions::GetDefaultKey() const {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h
index e5f7ce1..5a0b3b0 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options.h
@@ -14,6 +14,7 @@
 #include "base/time/time.h"
 
 namespace base {
+class DictionaryValue;
 class SingleThreadTaskRunner;
 }
 
@@ -65,6 +66,22 @@ class DataReductionProxyRequestOptions {
  public:
   static bool IsKeySetOnCommandLine();
 
+  // A pair of functions to convert the session and credentials for the Data
+  // Reduction Proxy to and from a single string; they are used to encode the
+  // session and credentials values into the |session_key| field of the
+  // ClientConfig protocol buffer. The delimiter used is '|', as it is not a
+  // valid character in a session or credentials string.
+  //
+  // CreateLocalSessionKey joins session and credentials with the delimiter.
+  static std::string CreateLocalSessionKey(const std::string& session,
+                                           const std::string& credentials);
+
+  // ParseLocalSessionKey splits the output of CreateLocalSessionKey into its
+  // two components. |session| and |credentials| must not be null.
+  static bool ParseLocalSessionKey(const std::string& session_key,
+                                   std::string* session,
+                                   std::string* credentials);
+
   // Constructs a DataReductionProxyRequestOptions object with the given
   // client type, config, and network task runner.
   DataReductionProxyRequestOptions(
@@ -104,6 +121,10 @@ class DataReductionProxyRequestOptions {
   // SetKeyOnIO is called.
   void SetKeyOnIO(const std::string& key);
 
+  // Populates |response| with the Data Reduction Proxy authentication info.
+  // Virtualized for testing.
+  virtual void PopulateConfigResponse(base::DictionaryValue* response) const;
+
  protected:
   void SetHeader(net::HttpRequestHeaders* headers);
 
@@ -114,7 +135,7 @@ class DataReductionProxyRequestOptions {
                                         const std::string& key);
   // Visible for testing.
   virtual base::Time Now() const;
-  virtual void RandBytes(void* output, size_t length);
+  virtual void RandBytes(void* output, size_t length) const;
 
   // Visible for testing.
   virtual std::string GetDefaultKey() const;
@@ -153,7 +174,7 @@ class DataReductionProxyRequestOptions {
   // the data reduction proxy.
   void ComputeCredentials(const base::Time& now,
                           std::string* session,
-                          std::string* credentials);
+                          std::string* credentials) const;
 
   // Generates and updates the session ID and credentials.
   void UpdateCredentials();
@@ -186,9 +207,9 @@ class DataReductionProxyRequestOptions {
   std::string lofi_;
   std::vector<std::string> experiments_;
 
-  // The last time the session was updated. Used to ensure that a session is
+  // The time at which the session expires. Used to ensure that a session is
   // never used for more than twenty-four hours.
-  base::Time last_credentials_update_time_;
+  base::Time credentials_expiration_time_;
 
   DataReductionProxyConfig* data_reduction_proxy_config_;
 
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options_unittest.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options_unittest.cc
index 70ea1f4..d34ebf2 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options_unittest.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_request_options_unittest.cc
@@ -28,7 +28,6 @@ const char kVersion[] = "0.1.2.3";
 const char kExpectedBuild[] = "2";
 const char kExpectedPatch[] = "3";
 const char kBogusVersion[] = "0.0";
-const char kTestKey[] = "test-key";
 const char kExpectedCredentials[] = "96bd72ec4a050ba60981743d41787768";
 const char kExpectedSession[] = "0-1633771873-1633771873-1633771873";
 
@@ -77,41 +76,6 @@ const Client kClient = Client::UNKNOWN;
 const char kClientStr[] = "";
 #endif
 
-class TestDataReductionProxyRequestOptions
-    : public DataReductionProxyRequestOptions {
- public:
-  TestDataReductionProxyRequestOptions(
-      Client client,
-      const std::string& version,
-      DataReductionProxyConfig* config,
-      scoped_refptr<base::SingleThreadTaskRunner> task_runner)
-      : DataReductionProxyRequestOptions(
-            client, version, config, task_runner) {}
-
-  std::string GetDefaultKey() const override {
-    return kTestKey;
-  }
-
-  base::Time Now() const override {
-    return base::Time::UnixEpoch() + now_offset_;
-  }
-
-  void RandBytes(void* output, size_t length) override {
-    char* c =  static_cast<char*>(output);
-    for (size_t i = 0; i < length; ++i) {
-      c[i] = 'a';
-    }
-  }
-
-  // Time after the unix epoch that Now() reports.
-  void set_offset(const base::TimeDelta& now_offset) {
-    now_offset_ = now_offset;
-  }
-
- private:
-  base::TimeDelta now_offset_;
-};
-
 void SetHeaderExpectations(const std::string& session,
                            const std::string& credentials,
                            const std::string& client,
@@ -339,4 +303,64 @@ TEST_F(DataReductionProxyRequestOptionsTest, ParseExperiments) {
   VerifyExpectedHeader(params()->DefaultOrigin(), expected_header);
 }
 
+TEST_F(DataReductionProxyRequestOptionsTest, ParseLocalSessionKey) {
+  const struct {
+    bool should_succeed;
+    std::string session_key;
+    std::string expected_session;
+    std::string expected_credentials;
+  } tests[] = {
+      {
+          true,
+          "foobar|1234",
+          "foobar",
+          "1234",
+      },
+      {
+          false,
+          "foobar|1234|foobaz",
+          std::string(),
+          std::string(),
+      },
+      {
+          false,
+          "foobar",
+          std::string(),
+          std::string(),
+      },
+      {
+          false,
+          std::string(),
+          std::string(),
+          std::string(),
+      },
+  };
+
+  std::string session;
+  std::string credentials;
+  for (size_t i = 0; i < arraysize(tests); ++i) {
+    EXPECT_EQ(tests[i].should_succeed,
+              DataReductionProxyRequestOptions::ParseLocalSessionKey(
+                  tests[i].session_key, &session, &credentials));
+    if (tests[i].should_succeed) {
+      EXPECT_EQ(tests[i].expected_session, session);
+      EXPECT_EQ(tests[i].expected_credentials, credentials);
+    }
+  }
+}
+
+TEST_F(DataReductionProxyRequestOptionsTest, PopulateConfigResponse) {
+  CreateRequestOptions(kBogusVersion);
+  scoped_ptr<base::DictionaryValue> values(new base::DictionaryValue());
+  request_options()->PopulateConfigResponse(values.get());
+  std::string session;
+  std::string expire_time;
+  EXPECT_TRUE(values->GetString("sessionKey", &session));
+  EXPECT_TRUE(values->GetString("expireTime", &expire_time));
+  EXPECT_EQ(
+      "0-1633771873-1633771873-1633771873|96bd72ec4a050ba60981743d41787768",
+      session);
+  EXPECT_EQ("1970-01-02T00:00:00.000Z", expire_time);
+}
+
 }  // namespace data_reduction_proxy
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.cc
index 422cd42..e9ea65ee 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.cc
@@ -22,8 +22,55 @@
 #include "net/url_request/url_request_job_factory_impl.h"
 #include "net/url_request/url_request_test_util.h"
 
+namespace {
+
+const char kTestKey[] = "test-key";
+
+}  // namespace
+
 namespace data_reduction_proxy {
 
+TestDataReductionProxyRequestOptions::TestDataReductionProxyRequestOptions(
+    Client client,
+    const std::string& version,
+    DataReductionProxyConfig* config,
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+    : DataReductionProxyRequestOptions(client, version, config, task_runner) {
+}
+
+std::string TestDataReductionProxyRequestOptions::GetDefaultKey() const {
+  return kTestKey;
+}
+
+base::Time TestDataReductionProxyRequestOptions::Now() const {
+  return base::Time::UnixEpoch() + now_offset_;
+}
+
+void TestDataReductionProxyRequestOptions::RandBytes(void* output,
+                                                     size_t length) const {
+  char* c = static_cast<char*>(output);
+  for (size_t i = 0; i < length; ++i) {
+    c[i] = 'a';
+  }
+}
+
+// Time after the unix epoch that Now() reports.
+void TestDataReductionProxyRequestOptions::set_offset(
+    const base::TimeDelta& now_offset) {
+  now_offset_ = now_offset;
+}
+
+MockDataReductionProxyRequestOptions::MockDataReductionProxyRequestOptions(
+    Client client,
+    const std::string& version,
+    DataReductionProxyConfig* config,
+    scoped_refptr<base::SingleThreadTaskRunner> task_runner)
+    : DataReductionProxyRequestOptions(client, version, config, task_runner) {
+}
+
+MockDataReductionProxyRequestOptions::~MockDataReductionProxyRequestOptions() {
+}
+
 MockDataReductionProxyService::MockDataReductionProxyService(
     scoped_ptr<DataReductionProxyStatisticsPrefs> statistics_prefs,
     DataReductionProxySettings* settings,
@@ -65,6 +112,7 @@ DataReductionProxyTestContext::Builder::Builder()
       use_mock_config_(false),
       use_test_configurator_(false),
       use_mock_service_(false),
+      use_mock_request_options_(false),
       skip_settings_initialization_(false) {
 }
 
@@ -120,6 +168,12 @@ DataReductionProxyTestContext::Builder::WithMockDataReductionProxyService() {
 }
 
 DataReductionProxyTestContext::Builder&
+DataReductionProxyTestContext::Builder::WithMockRequestOptions() {
+  use_mock_request_options_ = true;
+  return *this;
+}
+
+DataReductionProxyTestContext::Builder&
 DataReductionProxyTestContext::Builder::SkipSettingsInitialization() {
   skip_settings_initialization_ = true;
   return *this;
@@ -173,8 +227,15 @@ DataReductionProxyTestContext::Builder::Build() {
         configurator.get(), event_store.get()));
   }
 
-  scoped_ptr<DataReductionProxyRequestOptions> request_options(
-      new DataReductionProxyRequestOptions(client_, config.get(), task_runner));
+  scoped_ptr<DataReductionProxyRequestOptions> request_options;
+  if (use_mock_request_options_) {
+    test_context_flags |= USE_MOCK_REQUEST_OPTIONS;
+    request_options.reset(new MockDataReductionProxyRequestOptions(
+        client_, std::string(), config.get(), task_runner));
+  } else {
+    request_options.reset(new DataReductionProxyRequestOptions(
+        client_, config.get(), task_runner));
+  }
 
   scoped_ptr<DataReductionProxySettings> settings(
       new DataReductionProxySettings());
@@ -344,6 +405,14 @@ DataReductionProxyTestContext::mock_data_reduction_proxy_service()
       data_reduction_proxy_service());
 }
 
+MockDataReductionProxyRequestOptions*
+DataReductionProxyTestContext::mock_request_options() const {
+  DCHECK(test_context_flags_ &
+         DataReductionProxyTestContext::USE_MOCK_REQUEST_OPTIONS);
+  return reinterpret_cast<MockDataReductionProxyRequestOptions*>(
+      io_data_->request_options());
+}
+
 DataReductionProxyUsageStats::UnreachableCallback
 DataReductionProxyTestContext::unreachable_callback() const {
   return base::Bind(&DataReductionProxySettings::SetUnreachable,
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.h
index 589e391..9e0695ef 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_test_utils.h
@@ -5,9 +5,15 @@
 #ifndef COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_TEST_UTILS_H_
 #define COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_TEST_UTILS_H_
 
+#include <string>
+
 #include "base/macros.h"
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "base/time/time.h"
 #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/browser/data_reduction_proxy_service.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_settings_test_utils.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_usage_stats.h"
@@ -18,7 +24,6 @@ class TestingPrefServiceSimple;
 
 namespace base {
 class MessageLoopForUI;
-class SingleThreadTaskRunner;
 }
 
 namespace net {
@@ -40,6 +45,44 @@ class MockDataReductionProxyConfig;
 class TestDataReductionProxyConfig;
 class TestDataReductionProxyConfigurator;
 
+// Test version of |DataReductionProxyRequestOptions|.
+class TestDataReductionProxyRequestOptions
+    : public DataReductionProxyRequestOptions {
+ public:
+  TestDataReductionProxyRequestOptions(
+      Client client,
+      const std::string& version,
+      DataReductionProxyConfig* config,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
+  // Overrides of DataReductionProxyRequestOptions.
+  std::string GetDefaultKey() const override;
+  base::Time Now() const override;
+  void RandBytes(void* output, size_t length) const override;
+
+  // Time after the unix epoch that Now() reports.
+  void set_offset(const base::TimeDelta& now_offset);
+
+ private:
+  base::TimeDelta now_offset_;
+};
+
+// Mock version of |DataReductionProxyRequestOptions|.
+class MockDataReductionProxyRequestOptions
+    : public DataReductionProxyRequestOptions {
+ public:
+  MockDataReductionProxyRequestOptions(
+      Client client,
+      const std::string& version,
+      DataReductionProxyConfig* config,
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
+  ~MockDataReductionProxyRequestOptions();
+
+  MOCK_CONST_METHOD1(PopulateConfigResponse,
+                     void(base::DictionaryValue* response));
+};
+
 // Test version of |DataReductionProxyService|, which permits mocking of various
 // methods.
 class MockDataReductionProxyService : public DataReductionProxyService {
@@ -118,6 +161,10 @@ class DataReductionProxyTestContext {
     // |DataReductionProxyService|.
     Builder& WithMockDataReductionProxyService();
 
+    // Specifies the use of |MockDataReductionProxyRequestOptions| instead of
+    // |DataReductionProxyRequestOptions|.
+    Builder& WithMockRequestOptions();
+
     // Construct, but do not initialize the |DataReductionProxySettings| object.
     Builder& SkipSettingsInitialization();
 
@@ -134,6 +181,7 @@ class DataReductionProxyTestContext {
     bool use_mock_config_;
     bool use_test_configurator_;
     bool use_mock_service_;
+    bool use_mock_request_options_;
     bool skip_settings_initialization_;
   };
 
@@ -179,6 +227,10 @@ class DataReductionProxyTestContext {
   // be called if built with WithMockDataReductionProxyService.
   MockDataReductionProxyService* mock_data_reduction_proxy_service() const;
 
+  // Returns the underlying |MockDataReductionProxyRequestOptions|. This can
+  // only be called if built with WithMockRequestOptions.
+  MockDataReductionProxyRequestOptions* mock_request_options() const;
+
   // Obtains a callback for notifying that the Data Reduction Proxy is no
   // longer reachable.
   DataReductionProxyUsageStats::UnreachableCallback
@@ -233,6 +285,8 @@ class DataReductionProxyTestContext {
     SKIP_SETTINGS_INITIALIZATION = 0x4,
     // Permits mocking of the underlying |DataReductionProxyService|.
     USE_MOCK_SERVICE = 0x8,
+    // Permits mocking of the underlying |DataReductionProxyRequestOptions|.
+    USE_MOCK_REQUEST_OPTIONS = 0x10,
   };
 
   DataReductionProxyTestContext(
diff --git a/components/data_reduction_proxy/core/common/BUILD.gn b/components/data_reduction_proxy/core/common/BUILD.gn
index a28e6d0..6976004 100644
--- a/components/data_reduction_proxy/core/common/BUILD.gn
+++ b/components/data_reduction_proxy/core/common/BUILD.gn
@@ -7,6 +7,8 @@ import("//chrome/version.gni")
 static_library("common") {
   sources = [
     "data_reduction_proxy_bypass_type_list.h",
+    "data_reduction_proxy_client_config_parser.cc",
+    "data_reduction_proxy_client_config_parser.h",
     "data_reduction_proxy_config_values.h",
     "data_reduction_proxy_event_store.cc",
     "data_reduction_proxy_event_store.h",
@@ -25,6 +27,7 @@ static_library("common") {
   ]
   deps = [
     "//base",
+    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//net",
     "//url",
   ]
@@ -54,6 +57,7 @@ source_set("test_support") {
 source_set("unit_tests") {
   testonly = true
   sources = [
+    "data_reduction_proxy_client_config_parser_unittest.cc",
     "data_reduction_proxy_event_store_unittest.cc",
     "data_reduction_proxy_headers_unittest.cc",
     "data_reduction_proxy_params_unittest.cc",
@@ -64,6 +68,7 @@ source_set("unit_tests") {
     ":test_support",
     "//base",
     "//base/test:test_support",
+    "//components/data_reduction_proxy/proto:data_reduction_proxy_proto",
     "//net:test_support",
     "//testing/gtest",
   ]
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.cc
new file mode 100644
index 0000000..586ad68
--- /dev/null
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.cc
@@ -0,0 +1,166 @@
+// 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/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h"
+
+#include <string>
+
+#include "base/json/json_reader.h"
+#include "base/strings/stringprintf.h"
+#include "base/time/time.h"
+#include "base/values.h"
+
+namespace {
+
+// String representations of ProxyServer schemes.
+const char kSchemeHTTP[] = "HTTP";
+const char kSchemeHTTPS[] = "HTTPS";
+const char kSchemeQUIC[] = "QUIC";
+const char kSchemeUnspecified[] = "UNSPECIFIED";
+
+}  // namespace
+
+namespace data_reduction_proxy {
+
+namespace config_parser {
+
+std::string GetSchemeString(net::ProxyServer::Scheme scheme) {
+  switch (scheme) {
+    case net::ProxyServer::SCHEME_HTTP:
+      return kSchemeHTTP;
+    case net::ProxyServer::SCHEME_HTTPS:
+      return kSchemeHTTPS;
+    case net::ProxyServer::SCHEME_QUIC:
+      return kSchemeQUIC;
+    default:
+      return kSchemeUnspecified;
+  }
+}
+
+net::ProxyServer::Scheme SchemeFromProxyScheme(
+    ProxyServer_ProxyScheme proxy_scheme) {
+  switch (proxy_scheme) {
+    case ProxyServer_ProxyScheme_HTTP:
+      return net::ProxyServer::SCHEME_HTTP;
+    case ProxyServer_ProxyScheme_HTTPS:
+      return net::ProxyServer::SCHEME_HTTPS;
+    case ProxyServer_ProxyScheme_QUIC:
+      return net::ProxyServer::SCHEME_QUIC;
+    default:
+      return net::ProxyServer::SCHEME_INVALID;
+  }
+}
+
+ProxyServer_ProxyScheme GetProxyScheme(const std::string& scheme) {
+  if (scheme == kSchemeHTTP)
+    return ProxyServer_ProxyScheme_HTTP;
+
+  if (scheme == kSchemeHTTPS)
+    return ProxyServer_ProxyScheme_HTTPS;
+
+  if (scheme == kSchemeQUIC)
+    return ProxyServer_ProxyScheme_QUIC;
+
+  return ProxyServer_ProxyScheme_UNSPECIFIED;
+}
+
+std::string TimeToISO8601(const base::Time& time) {
+  base::Time::Exploded exploded;
+  time.UTCExplode(&exploded);
+  return base::StringPrintf(
+      "%04d-%02d-%02dT%02d:%02d:%02d.%03dZ", exploded.year, exploded.month,
+      exploded.day_of_month, exploded.hour, exploded.minute, exploded.second,
+      exploded.millisecond);
+}
+
+bool ISO8601ToTimestamp(const std::string& time, Timestamp* timestamp) {
+  base::Time t;
+  if (!base::Time::FromUTCString(time.c_str(), &t))
+    return false;
+
+  timestamp->set_seconds((t - base::Time::UnixEpoch()).InSeconds());
+  // Discard fractional seconds; it isn't worth the code effort to
+  // calculate it.
+  timestamp->set_nanos(0);
+  return true;
+}
+
+base::Time TimestampToTime(const Timestamp& timestamp) {
+  base::Time t = base::Time::UnixEpoch();
+  t += base::TimeDelta::FromSeconds(timestamp.seconds());
+  t += base::TimeDelta::FromMicroseconds(
+      timestamp.nanos() / base::Time::kNanosecondsPerMicrosecond);
+  return t;
+}
+
+bool ParseClientConfig(const std::string& config_data, ClientConfig* config) {
+  scoped_ptr<base::Value> parsed_data(base::JSONReader::Read(config_data));
+  if (!parsed_data)
+    return false;
+
+  const base::DictionaryValue* parsed_dict;
+  if (!parsed_data->GetAsDictionary(&parsed_dict))
+    return false;
+
+  std::string session_key;
+  if (!parsed_dict->GetString("sessionKey", &session_key))
+    return false;
+
+  config->set_session_key(session_key);
+
+  std::string expire_time;
+  if (!parsed_dict->GetString("expireTime", &expire_time))
+    return false;
+
+  if (!ISO8601ToTimestamp(expire_time, config->mutable_expire_time()))
+    return false;
+
+  const base::DictionaryValue* proxy_config_dict;
+  if (!parsed_dict->GetDictionary("proxyConfig", &proxy_config_dict))
+    return false;
+
+  ProxyConfig* proxy_config = config->mutable_proxy_config();
+
+  const base::ListValue* http_proxy_servers;
+  if (!proxy_config_dict->GetList("httpProxyServers", &http_proxy_servers))
+    return false;
+
+  base::ListValue::const_iterator it = http_proxy_servers->begin();
+  for (; it != http_proxy_servers->end(); ++it) {
+    const base::DictionaryValue* server_value;
+    if (!(*it)->GetAsDictionary(&server_value)) {
+      continue;
+    }
+
+    std::string scheme;
+    std::string host;
+    int port;
+    if (!server_value->GetString("scheme", &scheme)) {
+      continue;
+    }
+
+    if (!server_value->GetString("host", &host)) {
+      continue;
+    }
+
+    if (!server_value->GetInteger("port", &port)) {
+      continue;
+    }
+
+    ProxyServer_ProxyScheme proxy_scheme = GetProxyScheme(scheme);
+    if (proxy_scheme == ProxyServer_ProxyScheme_UNSPECIFIED)
+      continue;
+
+    ProxyServer* proxy_server = proxy_config->add_http_proxy_servers();
+    proxy_server->set_scheme(GetProxyScheme(scheme));
+    proxy_server->set_host(host);
+    proxy_server->set_port(port);
+  }
+
+  return true;
+}
+
+}  // namespace config_parser
+
+}  // namespace data_reduction_proxy
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h b/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h
new file mode 100644
index 0000000..461d945
--- /dev/null
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h
@@ -0,0 +1,51 @@
+// 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.
+
+#ifndef COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_CLIENT_CONFIG_RESPONSE_PARSER_H_
+#define COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_CLIENT_CONFIG_RESPONSE_PARSER_H_
+
+#include <string>
+
+#include "components/data_reduction_proxy/proto/client_config.pb.h"
+#include "net/proxy/proxy_server.h"
+
+namespace base {
+class Time;
+}
+
+namespace data_reduction_proxy {
+
+namespace config_parser {
+
+// Returns a string representation (which is actually the string representation
+// of ProxyServer_ProxyScheme) of a |net::ProxyServer::Scheme|.
+std::string GetSchemeString(net::ProxyServer::Scheme scheme);
+
+// Returns the |net::ProxyServer::Scheme| for a ProxyServer_ProxyScheme.
+net::ProxyServer::Scheme SchemeFromProxyScheme(
+    ProxyServer_ProxyScheme proxy_scheme);
+
+// Retrieves the ProxyServer_ProxyScheme for its string representation.
+ProxyServer_ProxyScheme GetProxyScheme(const std::string& scheme);
+
+// Returns the ISO-8601 representation of |time|.
+std::string TimeToISO8601(const base::Time& time);
+
+// Parses an ISO-8601 time string into a Timestamp proto.
+bool ISO8601ToTimestamp(const std::string& time, Timestamp* timestamp);
+
+// Returns the |base::Time| representation of |timestamp|.
+base::Time TimestampToTime(const Timestamp& timestamp);
+
+// Takes a JSON representation of a |ClientConfig| and populates |config|.
+// Returns false if the JSON has an unexpected structure.
+// TODO(jeremyim): This should be deprecated once gRPC support can be added
+// (which would give the binary proto instead of JSON).
+bool ParseClientConfig(const std::string& config_data, ClientConfig* config);
+
+}  // namespace config_parser
+
+}  // namespace data_reduction_proxy
+
+#endif  // COMPONENTS_DATA_REDUCTION_PROXY_CORE_COMMON_DATA_REDUCTION_PROXY_CLIENT_CONFIG_RESPONSE_PARSER_H_
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser_unittest.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser_unittest.cc
new file mode 100644
index 0000000..b7a9704
--- /dev/null
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser_unittest.cc
@@ -0,0 +1,228 @@
+// 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/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h"
+
+#include <string>
+
+#include "base/time/time.h"
+#include "components/data_reduction_proxy/proto/client_config.pb.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace data_reduction_proxy {
+
+namespace {
+
+const char kValidPreamble[] =
+    "{ \"sessionKey\": \"foobar\", "
+    "\"expireTime\": \"2100-12-31T23:59:59.999999Z\", "
+    "\"proxyConfig\": { \"httpProxyServers\": [";
+const char kValidPostamble[] = "] } }";
+
+}  // namespace
+
+TEST(ClientConfigParserTest, TimeToISO8601) {
+  const struct {
+    base::Time time;
+    std::string expected;
+  } tests[] = {
+      {
+          base::Time(),
+          "1601-01-01T00:00:00.000Z",
+      },
+      {
+          base::Time::UnixEpoch(),
+          "1970-01-01T00:00:00.000Z",
+      },
+  };
+
+  for (const auto& test : tests) {
+    EXPECT_EQ(test.expected, config_parser::TimeToISO8601(test.time));
+  }
+}
+
+TEST(ClientConfigParserTest, ISO8601ToTimestamp) {
+  const struct {
+    std::string time_string;
+    int64 epoch_seconds;
+  } tests[] = {
+      {
+          "1970-01-01T00:00:00.000Z",
+          0,
+      },
+      {
+          "1970-01-01T00:00:00.999Z",
+          0,
+      },
+      {
+          "1950-01-01T00:00:00.000Z",
+          -631152000,
+      },
+      {
+          "1950-01-01T00:00:00.500Z",
+          -631151999,  // Rounding of negative fractional values causes this.
+      },
+  };
+
+  for (const auto& test : tests) {
+    Timestamp timestamp;
+    EXPECT_TRUE(
+        config_parser::ISO8601ToTimestamp(test.time_string, &timestamp));
+    EXPECT_EQ(test.epoch_seconds, timestamp.seconds());
+    EXPECT_EQ(0, timestamp.nanos());
+  }
+}
+
+TEST(ClientConfigParserTest, ISO8601ToTimestampTestFailures) {
+  const std::string inputs[] = {
+      "",
+      "Not a time",
+      "1234",
+      "2099-43-12",
+      "2099-11-52",
+  };
+
+  for (const auto& input : inputs) {
+    Timestamp timestamp;
+    EXPECT_FALSE(config_parser::ISO8601ToTimestamp(input, &timestamp));
+  }
+}
+
+TEST(ClientConfigParserTest, TimestampToTime) {
+  base::Time::Exploded future = {
+      2100,
+      12,
+      5,
+      31,
+      23,
+      59,
+      59,
+      0,
+  };
+  const struct {
+    int64 timestamp_seconds;
+    int32 timestamp_nanos;
+    base::Time expected_time;
+  } tests[] = {
+      {
+        0,
+        0,
+        base::Time::UnixEpoch(),
+      },
+      {
+        24 * 60 * 60 - 1,
+        base::Time::kNanosecondsPerSecond - 1,
+        base::Time::UnixEpoch() + base::TimeDelta::FromDays(1) -
+            base::TimeDelta::FromMicroseconds(1),
+      },
+      {
+          // 2100-12-31T23:59:59.000Z
+          4133980799,
+          0,
+          base::Time::FromUTCExploded(future),
+      },
+  };
+
+  for (const auto& test : tests) {
+    Timestamp ts;
+    ts.set_seconds(test.timestamp_seconds);
+    ts.set_nanos(test.timestamp_nanos);
+    EXPECT_EQ(test.expected_time, config_parser::TimestampToTime(ts));
+  }
+}
+
+TEST(ClientConfigParserTest, SingleServer) {
+  const std::string inputs[] = {
+    "{ \"scheme\": \"HTTP\", \"host\": \"foo.com\", \"port\": 80 }",
+    "{ \"scheme\": \"HTTPS\", \"host\": \"foo.com\", \"port\": 443 }",
+    "{ \"scheme\": \"QUIC\", \"host\": \"foo.com\", \"port\": 443 }",
+  };
+
+  for (const auto& scheme_fragment : inputs) {
+    std::string input = kValidPreamble + scheme_fragment + kValidPostamble;
+    ClientConfig config;
+    EXPECT_TRUE(config_parser::ParseClientConfig(input, &config));
+    EXPECT_EQ(1, config.proxy_config().http_proxy_servers_size());
+  }
+}
+
+TEST(ClientConfigParserTest, MultipleServers) {
+  std::string input =
+      "{ \"scheme\": \"HTTP\", ""\"host\": \"foo.com\", \"port\": 80 }, "
+      "{ \"scheme\": \"HTTPS\", \"host\": \"foo.com\", \"port\": 443 }, "
+      "{ \"scheme\": \"QUIC\", \"host\": \"foo.com\", \"port\": 443 }";
+  ClientConfig config;
+  EXPECT_TRUE(config_parser::ParseClientConfig(
+      kValidPreamble + input + kValidPostamble, &config));
+  EXPECT_EQ(3, config.proxy_config().http_proxy_servers_size());
+}
+
+TEST(ClientConfigParserTest, FailureCases) {
+  const std::string inputs[] = {
+    "",
+    "invalid json",
+    // No sessionKey
+    "{ \"expireTime\": \"2100-12-31T23:59:59.999999Z\","
+      "\"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // No expireTime
+    "{ \"sessionKey\": \"foobar\","
+      "\"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // No proxyConfig
+    "{ \"sessionKey\": \"foobar\", "
+      "\"expireTime\": \"2100-12-31T23:59:59.999999Z\" }",
+    // No proxyConfig.httpProxyServers
+    "{ \"sessionKey\": \"foobar\", "
+      "\"expireTime\": \"2100-12-31T23:59:59.999999Z\", \"proxyConfig\": { } }",
+    // Invalid sessionKey
+    "{ \"sessionKey\": 12345, "
+      "\"expireTime\": \"2100-12-31T23:59:59.999999Z\","
+      " \"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // Invalid sessionKey
+    "{ \"sessionKey\": { }, "
+      "\"expireTime\": \"2100-12-31T23:59:59.999999Z\","
+      " \"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // Invalid sessionKey
+    "{ \"sessionKey\": [ ], "
+      "\"expireTime\": \"2100-12-31T23:59:59.999999Z\","
+      " \"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // Invalid expireTime
+    "{ \"sessionKey\": \"foobar\", "
+      "\"expireTime\": \"abcd\","
+      " \"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // Invalid expireTime
+    "{ \"sessionKey\": \"foobar\", "
+      "\"expireTime\": [ ],"
+      " \"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+    // Invalid expireTime
+    "{ \"sessionKey\": \"foobar\", "
+      "\"expireTime\": { },"
+      " \"proxyConfig\": { \"httpProxyServers\": [ ] } }",
+  };
+
+  for (const auto& input : inputs) {
+    ClientConfig config;
+    EXPECT_FALSE(config_parser::ParseClientConfig(input, &config));
+  }
+}
+
+TEST(ClientConfigParserTest, EmptyServerLists) {
+  const std::string inputs[] = {
+    "",
+    "{ }",
+    "{ \"scheme\": \"foo\", \"host\": \"foo.com\", \"port\": 80 }",
+    "{ \"scheme\": \"HTTP\", \"port\": 80 }",
+    "{ \"scheme\": \"HTTP\", \"host\": \"foo.com\" }",
+    "{ \"scheme\": \"HTTP\", \"host\": \"foo.com\", \"port\": \"bar\" }",
+    "{ \"scheme\": \"HTTP\", \"host\": 12345, \"port\": 80 }",
+  };
+
+  for (const auto& scheme_fragment : inputs) {
+    std::string input = kValidPreamble + scheme_fragment + kValidPostamble;
+    ClientConfig config;
+    EXPECT_TRUE(config_parser::ParseClientConfig(input, &config));
+    EXPECT_EQ(0, config.proxy_config().http_proxy_servers_size());
+  }
+}
+
+}  // namespace data_reduction_proxy
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
index 770e331..3769f3a 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.cc
@@ -7,8 +7,11 @@
 #include <string>
 
 #include "base/command_line.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_piece.h"
+#include "base/values.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_client_config_parser.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h"
 #include "net/base/host_port_pair.h"
 #include "net/proxy/proxy_server.h"
@@ -36,6 +39,11 @@ const char kDefaultWarmupUrl[] = "http://www.gstatic.com/generate_204";
 const char kAndroidOneIdentifier[] = "sprout";
 
 const char kQuicFieldTrial[] = "DataReductionProxyUseQuic";
+
+const char kConfigScheme[] = "scheme";
+const char kConfigHost[] = "host";
+const char kConfigPort[] = "port";
+
 }  // namespace
 
 namespace data_reduction_proxy {
@@ -386,6 +394,41 @@ bool DataReductionProxyParams::IsDataReductionProxy(
   return false;
 }
 
+void DataReductionProxyParams::PopulateConfigResponse(
+    base::DictionaryValue* response) const {
+  scoped_ptr<base::Value> proxy_config(new base::DictionaryValue());
+  if (!holdback_) {
+    base::DictionaryValue* proxy_config_dict = nullptr;
+    if (!proxy_config->GetAsDictionary(&proxy_config_dict))
+      return;
+
+    scoped_ptr<base::Value> proxy_servers(new base::ListValue());
+    base::ListValue* proxy_servers_list = nullptr;
+    if (!proxy_servers->GetAsList(&proxy_servers_list))
+      return;
+
+    proxy_servers->GetAsList(&proxy_servers_list);
+    scoped_ptr<base::DictionaryValue> server(new base::DictionaryValue());
+
+    server->SetString(kConfigScheme,
+                      config_parser::GetSchemeString(origin_.scheme()));
+    server->SetString(kConfigHost, origin_.host_port_pair().host());
+    server->SetInteger(kConfigPort, origin_.host_port_pair().port());
+    proxy_servers_list->Append(server.release());
+    server.reset(new base::DictionaryValue());
+
+    server->SetString(kConfigScheme, config_parser::GetSchemeString(
+                                         fallback_origin_.scheme()));
+    server->SetString(kConfigHost, fallback_origin_.host_port_pair().host());
+    server->SetInteger(kConfigPort, fallback_origin_.host_port_pair().port());
+    proxy_servers_list->Append(server.release());
+
+    proxy_config_dict->Set("httpProxyServers", proxy_servers.Pass());
+  }
+
+  response->Set("proxyConfig", proxy_config.Pass());
+}
+
 // Returns the data reduction proxy primary origin.
 const net::ProxyServer& DataReductionProxyParams::origin() const {
   return origin_;
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
index 256c6c4..30c51ff 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_params.h
@@ -13,6 +13,7 @@
 #include "url/gurl.h"
 
 namespace base {
+class DictionaryValue;
 class TimeDelta;
 }
 
@@ -131,6 +132,10 @@ class DataReductionProxyParams : public DataReductionProxyConfigValues {
   // If true, uses QUIC instead of SPDY to connect to proxies that use TLS.
   void EnableQuic(bool enable);
 
+  // Populates |response| with the Data Reduction Proxy server configuration.
+  // Virtual for mocking.
+  virtual void PopulateConfigResponse(base::DictionaryValue* response) const;
+
   // Overrides of |DataReductionProxyConfigValues|
   bool UsingHTTPTunnel(const net::HostPortPair& proxy_server) const override;
 
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
index e2e8120..aa50741 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_params_unittest.cc
@@ -7,6 +7,7 @@
 #include <map>
 
 #include "base/command_line.h"
+#include "base/values.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params_test_utils.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h"
 #include "net/proxy/proxy_server.h"
@@ -766,4 +767,30 @@ TEST_F(DataReductionProxyParamsTest, AndroidOnePromoFieldTrial) {
       "google/hammerhead/hammerhead:5.0/LRX210/1570415:user/release-keys"));
 }
 
+TEST_F(DataReductionProxyParamsTest, PopulateConfigResponse) {
+  DataReductionProxyParams params(
+      DataReductionProxyParams::kAllowed |
+      DataReductionProxyParams::kAlternativeAllowed);
+  scoped_ptr<base::DictionaryValue> values(new base::DictionaryValue());
+  params.PopulateConfigResponse(values.get());
+  base::DictionaryValue* proxy_config;
+  EXPECT_TRUE(values->GetDictionary("proxyConfig", &proxy_config));
+  base::ListValue* proxy_servers;
+  EXPECT_TRUE(proxy_config->GetList("httpProxyServers", &proxy_servers));
+  EXPECT_TRUE(proxy_servers->GetSize() == 2);
+  base::DictionaryValue* server;
+  EXPECT_TRUE(proxy_servers->GetDictionary(0, &server));
+  std::string host;
+  int port;
+  EXPECT_TRUE(server->GetString("host", &host));
+  EXPECT_TRUE(server->GetInteger("port", &port));
+  EXPECT_EQ(params.origin().host_port_pair().host(), host);
+  EXPECT_EQ(params.origin().host_port_pair().port(), port);
+  EXPECT_TRUE(proxy_servers->GetDictionary(1, &server));
+  EXPECT_TRUE(server->GetString("host", &host));
+  EXPECT_TRUE(server->GetInteger("port", &port));
+  EXPECT_EQ(params.fallback_origin().host_port_pair().host(), host);
+  EXPECT_EQ(params.fallback_origin().host_port_pair().port(), port);
+}
+
 }  // namespace data_reduction_proxy
diff --git a/components/data_reduction_proxy/proto/BUILD.gn b/components/data_reduction_proxy/proto/BUILD.gn
new file mode 100644
index 0000000..889c106
--- /dev/null
+++ b/components/data_reduction_proxy/proto/BUILD.gn
@@ -0,0 +1,11 @@
+# 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.
+
+import("//third_party/protobuf/proto_library.gni")
+
+proto_library("data_reduction_proxy_proto") {
+  sources = [
+    "client_config.proto",
+  ]
+}
diff --git a/components/data_reduction_proxy/proto/client_config.proto b/components/data_reduction_proxy/proto/client_config.proto
new file mode 100644
index 0000000..f2c796c
--- /dev/null
+++ b/components/data_reduction_proxy/proto/client_config.proto
@@ -0,0 +1,70 @@
+// 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.
+
+syntax = "proto2";
+
+option optimize_for = LITE_RUNTIME;
+
+package data_reduction_proxy;
+
+// The client configuration information for using the Data Saver service.
+message ClientConfig {
+  // An opaque per-session key assigned by the server which permits use of the
+  // Data Saver HTTP proxy servers.
+  optional string session_key = 1;
+  // The time at which the secure_session_key is no longer valid. This is
+  // enforced by the Data Saver service, and is provided to permit the client
+  // to request a new session key prior to expiration.
+  optional Timestamp expire_time = 2;
+  // The DataSaver proxy configuration that is valid for the session.
+  optional ProxyConfig proxy_config = 3;
+}
+
+// A Timestamp represents a point in time independent of any time zone
+// or calendar, represented as seconds and fractions of seconds at
+// nanosecond resolution in UTC Epoch time.
+message Timestamp {
+  // Represents seconds of UTC time since Unix epoch
+  // 1970-01-01T00:00:00Z. Must be from from 0001-01-01T00:00:00Z to
+  // 9999-12-31T23:59:59Z inclusive.
+  optional int64 seconds = 1;
+
+  // Non-negative fractions of a second at nanosecond resolution. Negative
+  // second values with fractions must still have non-negative nanos values
+  // that count forward in time. Must be from 0 to 999,999,999
+  // inclusive.
+  optional int32 nanos = 2;
+}
+
+// Data Saver proxy configuration.
+message ProxyConfig {
+  // Provides proxy server information for HTTP URIs.
+  repeated ProxyServer http_proxy_servers = 1;
+}
+
+// Configuration information for a specific proxy server.
+message ProxyServer {
+  // The scheme of the proxy server.
+  enum ProxyScheme {
+    // The proxy scheme is unspecified.
+    UNSPECIFIED = 0;
+    // HTTP
+    HTTP = 1;
+    // HTTPS
+    HTTPS = 2;
+    // HTTPS over QUIC
+    QUIC = 3;
+  }
+
+  // The scheme for the proxy server.
+  optional ProxyScheme scheme = 1;
+  // The host name for the proxy server.
+  optional string host = 2;
+  // The port number for the proxy server.
+  optional int32 port = 3;
+}
+
+// Request object to create a client configuration object.
+message CreateClientConfigRequest {
+}