Remove BooleanPrefMember usage from Data Reduction Proxy IO classes.

The UI objects (specifically DataReductionProxySettings) already creates
a BooleanPrefMember for kDataReductionProxyEnabled and checks for changes
on it, then propagates this information to DataReductionProxyIOData via
DataReductionProxyIOData::SetProxyPrefs.

It also negates the need to pass a BooleanPrefMember to BypassStats when
ultimately all we care about is the boolean value.

BUG=472290

Review URL: https://codereview.chromium.org/1057473003

Cr-Commit-Position: refs/heads/master@{#327138}

12 files changed, 45 insertions, 79 deletions

diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
index 87e94d2..d179657 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.cc
@@ -7,7 +7,6 @@
 #include "base/callback.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
-#include "base/prefs/pref_member.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_tamper_detection.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
@@ -170,7 +169,7 @@ DataReductionProxyBypassStats::GetBypassType() const {
 
 void DataReductionProxyBypassStats::RecordBytesHistograms(
     const net::URLRequest& request,
-    const BooleanPrefMember& data_reduction_proxy_enabled,
+    bool data_reduction_proxy_enabled,
     const net::ProxyConfig& data_reduction_proxy_config) {
   RecordBypassedBytesHistograms(request, data_reduction_proxy_enabled,
                                 data_reduction_proxy_config);
@@ -226,12 +225,12 @@ void DataReductionProxyBypassStats::OnConnectComplete(
 
 void DataReductionProxyBypassStats::RecordBypassedBytesHistograms(
     const net::URLRequest& request,
-    const BooleanPrefMember& data_reduction_proxy_enabled,
+    bool data_reduction_proxy_enabled,
     const net::ProxyConfig& data_reduction_proxy_config) {
   int64 content_length = request.received_response_content_length();
 
   // Only record histograms when the data reduction proxy is enabled.
-  if (!data_reduction_proxy_enabled.GetValue())
+  if (!data_reduction_proxy_enabled)
     return;
 
   // TODO(bengr): Add histogram(s) for byte counts of unsupported schemes, e.g.,
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h
index efff8d1..dcec95e 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h
@@ -6,7 +6,6 @@
 #define COMPONENTS_DATA_REDUCTION_PROXY_CORE_BROWSER_DATA_REDUCTION_PROXY_BYPASS_STATS_H_
 
 #include "base/callback.h"
-#include "base/prefs/pref_member.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_headers.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/network_change_notifier.h"
@@ -68,7 +67,7 @@ class DataReductionProxyBypassStats
   // completed URLRequest |request|.
   void RecordBytesHistograms(
       const net::URLRequest& request,
-      const BooleanPrefMember& data_reduction_proxy_enabled,
+      bool data_reduction_proxy_enabled,
       const net::ProxyConfig& data_reduction_proxy_config);
 
   // Called by |ChromeNetworkDelegate| when a proxy is put into the bad proxy
@@ -104,7 +103,7 @@ class DataReductionProxyBypassStats
   // tells us the state of the kDataReductionProxyEnabled preference.
   void RecordBypassedBytesHistograms(
       const net::URLRequest& request,
-      const BooleanPrefMember& data_reduction_proxy_enabled,
+      bool data_reduction_proxy_enabled,
       const net::ProxyConfig& data_reduction_proxy_config);
 
   // Records UMA of the number of response bytes of responses that are expected
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
index 5a4c5d8..37ecf96 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.cc
@@ -5,11 +5,8 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 
 #include "base/bind.h"
-#include "base/command_line.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
-#include "base/prefs/pref_member.h"
-#include "base/single_thread_task_runner.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_protocol.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_compression_stats.h"
@@ -93,13 +90,14 @@ DataReductionProxyIOData::DataReductionProxyIOData(
     net::NetLog* net_log,
     scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
+    bool enabled,
     bool enable_quic,
     const std::string& user_agent)
     : client_(client),
       net_log_(net_log),
       io_task_runner_(io_task_runner),
       ui_task_runner_(ui_task_runner),
-      shutdown_on_ui_(false),
+      enabled_(enabled),
       url_request_context_getter_(nullptr),
       basic_url_request_context_getter_(
           new BasicHTTPURLRequestContextGetter(user_agent, io_task_runner)),
@@ -148,26 +146,14 @@ DataReductionProxyIOData::DataReductionProxyIOData(
  }
 
  DataReductionProxyIOData::DataReductionProxyIOData()
-     : shutdown_on_ui_(false),
-       url_request_context_getter_(nullptr),
-       weak_factory_(this) {
+     : url_request_context_getter_(nullptr), weak_factory_(this) {
 }
 
 DataReductionProxyIOData::~DataReductionProxyIOData() {
-  DCHECK(shutdown_on_ui_);
-}
-
-void DataReductionProxyIOData::InitOnUIThread(PrefService* pref_service) {
-  DCHECK(ui_task_runner_->BelongsToCurrentThread());
-  enabled_.Init(prefs::kDataReductionProxyEnabled, pref_service);
-  enabled_.MoveToThread(io_task_runner_);
 }
 
 void DataReductionProxyIOData::ShutdownOnUIThread() {
-  DCHECK(!shutdown_on_ui_);
   DCHECK(ui_task_runner_->BelongsToCurrentThread());
-  enabled_.Destroy();
-  shutdown_on_ui_ = true;
 }
 
 void DataReductionProxyIOData::SetDataReductionProxyService(
@@ -197,9 +183,7 @@ void DataReductionProxyIOData::InitializeOnIOThread() {
 
 bool DataReductionProxyIOData::IsEnabled() const {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
-  return enabled_.GetValue() ||
-         base::CommandLine::ForCurrentProcess()->HasSwitch(
-             switches::kEnableDataReductionProxy);
+  return enabled_;
 }
 
 void DataReductionProxyIOData::RetrieveConfig() {
@@ -225,7 +209,7 @@ DataReductionProxyIOData::CreateNetworkDelegate(
           wrapped_network_delegate.Pass(), config_.get(),
           request_options_.get(), configurator_.get()));
   if (track_proxy_bypass_statistics)
-    network_delegate->InitIODataAndUMA(this, &enabled_, bypass_stats_.get());
+    network_delegate->InitIODataAndUMA(this, bypass_stats_.get());
   return network_delegate.Pass();
 }
 
@@ -233,6 +217,7 @@ void DataReductionProxyIOData::SetProxyPrefs(bool enabled,
                                              bool alternative_enabled,
                                              bool at_startup) {
   DCHECK(io_task_runner_->BelongsToCurrentThread());
+  enabled_ = enabled;
   config_->SetProxyConfig(enabled, alternative_enabled, at_startup);
 }
 
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
index 9a6f3b8..4acbc48 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h
@@ -9,7 +9,7 @@
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
-#include "base/prefs/pref_member.h"
+#include "base/single_thread_task_runner.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_debug_ui_service.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_delegate.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_metrics.h"
@@ -42,23 +42,21 @@ class DataReductionProxyIOData : public DataReductionProxyEventStorageDelegate {
  public:
   // Constructs a DataReductionProxyIOData object. |param_flags| is used to
   // set information about the DNS names used by the proxy, and allowable
-  // configurations.
+  // configurations. |enabled| sets the initial state of the Data Reduction
+  // Proxy.
   DataReductionProxyIOData(
       const Client& client,
       int param_flags,
       net::NetLog* net_log,
       scoped_refptr<base::SingleThreadTaskRunner> io_task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
+      bool enabled,
       bool enable_quic,
       const std::string& user_agent);
 
   virtual ~DataReductionProxyIOData();
 
-  // Initializes preferences, including a preference to track whether the
-  // Data Reduction Proxy is enabled.
-  void InitOnUIThread(PrefService* pref_service);
-
-  // Destroys the statistics preferences.
+  // Performs UI thread specific shutdown logic.
   void ShutdownOnUIThread();
 
   // Sets the Data Reduction Proxy service after it has been created.
@@ -205,12 +203,9 @@ class DataReductionProxyIOData : public DataReductionProxyEventStorageDelegate {
   scoped_refptr<base::SingleThreadTaskRunner> io_task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
-  // Used
-  bool shutdown_on_ui_;
-
-  // Preference that determines if the Data Reduction Proxy has been enabled
-  // by the user. In practice, this can be overridden by the command line.
-  BooleanPrefMember enabled_;
+  // Whether the Data Reduction Proxy has been enabled or not by the user. In
+  // practice, this can be overridden by the command line.
+  bool enabled_;
 
   // The net::URLRequestContextGetter used for making URL requests.
   net::URLRequestContextGetter* url_request_context_getter_;
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data_unittest.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data_unittest.cc
index 4caf215..24fc634 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data_unittest.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data_unittest.cc
@@ -94,8 +94,8 @@ class DataReductionProxyIODataTest : public testing::Test {
 TEST_F(DataReductionProxyIODataTest, TestConstruction) {
   scoped_ptr<DataReductionProxyIOData> io_data(new DataReductionProxyIOData(
       Client::UNKNOWN, DataReductionProxyParams::kAllowed, net_log(),
-      message_loop_proxy(), message_loop_proxy(), false /* enable_quic */,
-      std::string() /* user_agent */));
+      message_loop_proxy(), message_loop_proxy(), false /* enabled */,
+      false /* enable_quic */, std::string() /* user_agent */));
 
   // Check that the SimpleURLRequestContextGetter uses vanilla HTTP.
   net::URLRequestContext* request_context =
@@ -141,9 +141,6 @@ TEST_F(DataReductionProxyIODataTest, TestConstruction) {
                                  true);
   EXPECT_NE(nullptr, io_data->bypass_stats());
 
-  // The Data Reduction Proxy isn't actually enabled here.
-  io_data->InitOnUIThread(prefs());
-  EXPECT_FALSE(io_data->IsEnabled());
   io_data->ShutdownOnUIThread();
 }
 
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 6ef70dc..9a66acd 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
@@ -7,7 +7,6 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/metrics/histogram.h"
-#include "base/prefs/pref_service.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_bypass_stats.h"
@@ -81,7 +80,6 @@ DataReductionProxyNetworkDelegate::DataReductionProxyNetworkDelegate(
     : LayeredNetworkDelegate(network_delegate.Pass()),
       received_content_length_(0),
       original_content_length_(0),
-      data_reduction_proxy_enabled_(nullptr),
       data_reduction_proxy_config_(config),
       data_reduction_proxy_bypass_stats_(nullptr),
       data_reduction_proxy_request_options_(request_options),
@@ -96,12 +94,9 @@ DataReductionProxyNetworkDelegate::~DataReductionProxyNetworkDelegate() {
 
 void DataReductionProxyNetworkDelegate::InitIODataAndUMA(
     DataReductionProxyIOData* io_data,
-    BooleanPrefMember* data_reduction_proxy_enabled,
     DataReductionProxyBypassStats* bypass_stats) {
-  DCHECK(data_reduction_proxy_enabled);
   DCHECK(bypass_stats);
   data_reduction_proxy_io_data_ = io_data;
-  data_reduction_proxy_enabled_ = data_reduction_proxy_enabled;
   data_reduction_proxy_bypass_stats_ = bypass_stats;
 }
 
@@ -191,10 +186,9 @@ void DataReductionProxyNetworkDelegate::OnCompletedInternal(
                                   original_content_length,
                                   freshness_lifetime);
 
-    if (data_reduction_proxy_enabled_ &&
-        data_reduction_proxy_bypass_stats_) {
+    if (data_reduction_proxy_io_data_ && data_reduction_proxy_bypass_stats_) {
       data_reduction_proxy_bypass_stats_->RecordBytesHistograms(
-          *request, *data_reduction_proxy_enabled_,
+          *request, data_reduction_proxy_io_data_->IsEnabled(),
           configurator_->GetProxyConfig());
     }
     DVLOG(2) << __FUNCTION__
@@ -210,10 +204,10 @@ void DataReductionProxyNetworkDelegate::AccumulateContentLength(
     DataReductionProxyRequestType request_type) {
   DCHECK_GE(received_content_length, 0);
   DCHECK_GE(original_content_length, 0);
-  if (data_reduction_proxy_enabled_) {
+  if (data_reduction_proxy_io_data_) {
     data_reduction_proxy_io_data_->UpdateContentLengths(
         received_content_length, original_content_length,
-        data_reduction_proxy_enabled_->GetValue(), request_type);
+        data_reduction_proxy_io_data_->IsEnabled(), request_type);
   }
   received_content_length_ += received_content_length;
   original_content_length_ += original_content_length;
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.h b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.h
index 8cb016e..0290d6e 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.h
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.h
@@ -13,12 +13,7 @@
 #include "net/base/layered_network_delegate.h"
 #include "net/proxy/proxy_retry_info.h"
 
-template<class T> class PrefMember;
-
-typedef PrefMember<bool> BooleanPrefMember;
-
 class GURL;
-class PrefService;
 
 namespace net {
 class HttpResponseHeaders;
@@ -64,7 +59,6 @@ class DataReductionProxyNetworkDelegate : public net::LayeredNetworkDelegate {
   // report UMA.
   void InitIODataAndUMA(
       DataReductionProxyIOData* io_data,
-      BooleanPrefMember* data_reduction_proxy_enabled,
       DataReductionProxyBypassStats* bypass_stats);
 
   // Creates a |Value| summary of the state of the network session. The caller
@@ -117,9 +111,6 @@ class DataReductionProxyNetworkDelegate : public net::LayeredNetworkDelegate {
   // Total original size of all content before it was transferred.
   int64 original_content_length_;
 
-  // Weak, owned by our owner.
-  BooleanPrefMember* data_reduction_proxy_enabled_;
-
   // All raw Data Reduction Proxy pointers must outlive |this|.
   DataReductionProxyConfig* data_reduction_proxy_config_;
 
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.cc
index 57f18bb..0c5b802b 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_settings.cc
@@ -13,6 +13,7 @@
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_config.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_io_data.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_service.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_pref_names.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h"
 
@@ -21,13 +22,6 @@ namespace {
 const char kUMAProxyStartupStateHistogram[] =
     "DataReductionProxy.StartupState";
 
-bool IsEnabledOnCommandLine() {
-  const base::CommandLine& command_line =
-      *base::CommandLine::ForCurrentProcess();
-  return command_line.HasSwitch(
-      data_reduction_proxy::switches::kEnableDataReductionProxy);
-}
-
 bool IsLoFiEnabledOnCommandLine() {
   const base::CommandLine& command_line =
       *base::CommandLine::ForCurrentProcess();
@@ -116,7 +110,8 @@ void DataReductionProxySettings::SetCallbackToRegisterSyntheticFieldTrial(
 }
 
 bool DataReductionProxySettings::IsDataReductionProxyEnabled() const {
-  return spdy_proxy_auth_enabled_.GetValue() || IsEnabledOnCommandLine();
+  return spdy_proxy_auth_enabled_.GetValue() ||
+         DataReductionProxyParams::ShouldForceEnableDataReductionProxy();
 }
 
 bool DataReductionProxySettings::CanUseDataReductionProxy(
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 c784796..f71ce8d 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
@@ -177,7 +177,8 @@ TestDataReductionProxyIOData::TestDataReductionProxyIOData(
     scoped_ptr<DataReductionProxyEventCreator> event_creator,
     scoped_ptr<DataReductionProxyRequestOptions> request_options,
     scoped_ptr<DataReductionProxyConfigurator> configurator,
-    scoped_ptr<DataReductionProxyConfigServiceClient> config_client)
+    scoped_ptr<DataReductionProxyConfigServiceClient> config_client,
+    bool enabled)
     : DataReductionProxyIOData() {
   io_task_runner_ = task_runner;
   ui_task_runner_ = task_runner;
@@ -191,10 +192,10 @@ TestDataReductionProxyIOData::TestDataReductionProxyIOData(
                                 base::Unretained(this))));
   io_task_runner_ = task_runner;
   ui_task_runner_ = task_runner;
+  enabled_ = enabled;
 }
 
 TestDataReductionProxyIOData::~TestDataReductionProxyIOData() {
-  shutdown_on_ui_ = true;
 }
 
 DataReductionProxyTestContext::Builder::Builder()
@@ -386,8 +387,8 @@ DataReductionProxyTestContext::Builder::Build() {
   scoped_ptr<TestDataReductionProxyIOData> io_data(
       new TestDataReductionProxyIOData(
           task_runner, config.Pass(), event_creator.Pass(),
-          request_options.Pass(), configurator.Pass(), config_client.Pass()));
-  io_data->InitOnUIThread(pref_service.get());
+          request_options.Pass(), configurator.Pass(), config_client.Pass(),
+          true /* enabled */));
   io_data->SetSimpleURLRequestContextGetter(request_context_getter);
 
   scoped_ptr<DataReductionProxyTestContext> test_context(
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 e199098..81a8984 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
@@ -167,7 +167,8 @@ class TestDataReductionProxyIOData : public DataReductionProxyIOData {
       scoped_ptr<DataReductionProxyEventCreator> event_creator,
       scoped_ptr<DataReductionProxyRequestOptions> request_options,
       scoped_ptr<DataReductionProxyConfigurator> configurator,
-      scoped_ptr<DataReductionProxyConfigServiceClient> config_client);
+      scoped_ptr<DataReductionProxyConfigServiceClient> config_client,
+      bool enabled);
   ~TestDataReductionProxyIOData() override;
 
   DataReductionProxyConfigurator* configurator() const {
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 79205a2..d62b73b 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
@@ -102,7 +102,6 @@ bool DataReductionProxyParams::IsIncludedInAndroidOnePromoFieldTrial(
 bool DataReductionProxyParams::IsLoFiEnabled() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
-
 }
 
 //static
@@ -136,6 +135,12 @@ bool DataReductionProxyParams::IsConfigClientEnabled() {
       data_reduction_proxy::switches::kEnableDataReductionProxyConfigClient);
 }
 
+// static
+bool DataReductionProxyParams::ShouldForceEnableDataReductionProxy() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      data_reduction_proxy::switches::kEnableDataReductionProxy);
+}
+
 void DataReductionProxyParams::EnableQuic(bool enable) {
   quic_enabled_ = enable;
   DCHECK(!quic_enabled_ || IsIncludedInQuicFieldTrial());
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 0f6aea8..fe345ec 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
@@ -116,6 +116,10 @@ class DataReductionProxyParams : public DataReductionProxyConfigValues {
   // Returns true if the Data Reduction Proxy config client should be used.
   static bool IsConfigClientEnabled();
 
+  // Returns true if the Data Reduction Proxy is forced to be enabled from the
+  // command line.
+  static bool ShouldForceEnableDataReductionProxy();
+
   // Constructs configuration parameters. If |kAllowed|, then the standard
   // data reduction proxy configuration is allowed to be used. If
   // |kfallbackAllowed| a fallback proxy can be used if the primary proxy is