Tri-state Data Reduction Proxy Lo-Fi flag

Make the Lo-Fi flag MULTI_VALUE_TYPE with modes always-on,
cellular-only, and disabled.

BUG=497437

Review URL: https://codereview.chromium.org/1159783005

Cr-Commit-Position: refs/heads/master@{#334021}

15 files changed, 147 insertions, 37 deletions

diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index f250d49..a11f843 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -6467,11 +6467,20 @@ Keep your key file in a safe place. You will need it to create new versions of y
           Use Data Saver with bypass warnings. The proxy must be enabled in settings for this flag to take effect.
         </message>
       </if>
-      <message name="IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_NAME" desc="An about::flags experiment title to enable/disable Data Saver Lo-Fi">
-         Enable Data Saver Lo-Fi mode
+      <message name="IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_NAME" desc="An about::flags experiment title to enable/disable Data Saver Lo-Fi">
+         Data Saver Lo-Fi mode
       </message>
-      <message name="IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_DESCRIPTION" desc="Describes an about::flags experiment to enable/disable Data Saver Lo-Fi">
-         Puts the Data Saver in Lo-Fi mode when enabled.
+      <message name="IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_DESCRIPTION" desc="Describes an about::flags experiment to enable/disable Data Saver Lo-Fi">
+         Forces Data Saver Lo-Fi mode to be always enabled, enabled only on cellular connections, or disabled. Data Saver must be enabled for Lo-Fi mode to be used.
+      </message>
+      <message name="IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_ALWAYS_ON" desc="Option for IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_NAME to enable Lo-Fi always on">
+         Always on
+      </message>
+      <message name="IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_CELLULAR_ONLY" desc="Option for IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_NAME to enable Lo-Fi only on celluar connections">
+         Cellular only
+      </message>
+      <message name="IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_DISABLED" desc="Option for IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_NAME to disable Lo-Fi">
+         Disable
       </message>
       <message name="IDS_FLAGS_DATA_REDUCTION_PROXY_RESET_SAVINGS_NAME" desc="Title in about::flags to clear data savings obtained with data reduction proxy when Chrome restarts">
          Clear data savings on startup
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 68b01be..af1c4b8 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -215,6 +215,20 @@ const Experiment::Choice kMarkNonSecureAsChoices[] = {
         switches::kMarkNonSecureAs, switches::kMarkNonSecureAsDubious}
 };
 
+const Experiment::Choice kDataReductionProxyLoFiChoices[] = {
+    { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
+    { IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_ALWAYS_ON,
+        data_reduction_proxy::switches::kDataReductionProxyLoFi,
+        data_reduction_proxy::switches::kDataReductionProxyLoFiValueAlwaysOn},
+    { IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_CELLULAR_ONLY,
+        data_reduction_proxy::switches::kDataReductionProxyLoFi,
+        data_reduction_proxy::switches::
+            kDataReductionProxyLoFiValueCellularOnly},
+    { IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_DISABLED,
+        data_reduction_proxy::switches::kDataReductionProxyLoFi,
+        data_reduction_proxy::switches::kDataReductionProxyLoFiValueDisabled}
+};
+
 const Experiment::Choice kShowSavedCopyChoices[] = {
   { IDS_GENERIC_EXPERIMENT_CHOICE_DEFAULT, "", "" },
   { IDS_FLAGS_ENABLE_SHOW_SAVED_COPY_PRIMARY,
@@ -2226,12 +2240,11 @@ const Experiment kExperiments[] = {
   },
 #endif  // defined(OS_CHROMEOS)
   {
-    "enable-data-reduction-proxy-lo-fi",
-    IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_NAME,
-    IDS_FLAGS_ENABLE_DATA_REDUCTION_PROXY_LO_FI_DESCRIPTION,
+    "data-reduction-proxy-lo-fi",
+    IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_NAME,
+    IDS_FLAGS_DATA_REDUCTION_PROXY_LO_FI_DESCRIPTION,
     kOsAll,
-    SINGLE_VALUE_TYPE(data_reduction_proxy::switches::
-                      kEnableDataReductionProxyLoFi)
+    MULTI_VALUE_TYPE(kDataReductionProxyLoFiChoices)
   },
   {
     "clear-data-reduction-proxy-data-savings",
@@ -2552,9 +2565,9 @@ bool SkipConditionalExperiment(const Experiment& experiment,
       channel != chrome::VersionInfo::CHANNEL_DEV) {
     return true;
   }
-  // enable-data-reduction-proxy-lo-fi is only available for Chromium builds and
+  // data-reduction-proxy-lo-fi is only available for Chromium builds and
   // the Canary/Dev channel.
-  if (!strcmp("enable-data-reduction-proxy-lo-fi", experiment.internal_name) &&
+  if (!strcmp("data-reduction-proxy-lo-fi", experiment.internal_name) &&
       channel != chrome::VersionInfo::CHANNEL_DEV &&
       channel != chrome::VersionInfo::CHANNEL_CANARY &&
       channel != chrome::VersionInfo::CHANNEL_UNKNOWN) {
diff --git a/components/data_reduction_proxy/content/browser/data_reduction_proxy_message_filter_unittest.cc b/components/data_reduction_proxy/content/browser/data_reduction_proxy_message_filter_unittest.cc
index 77f07da..cca2197 100644
--- a/components/data_reduction_proxy/content/browser/data_reduction_proxy_message_filter_unittest.cc
+++ b/components/data_reduction_proxy/content/browser/data_reduction_proxy_message_filter_unittest.cc
@@ -128,9 +128,9 @@ TEST_F(DataReductionProxyMessageFilterTest, TestOnDataReductionProxyStatus) {
     bool is_data_reduction_proxy = false;
 
     if (tests[i].lofi_on_through_switch) {
-      base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
-      command_line->AppendSwitch(
-          data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kDataReductionProxyLoFi,
+          switches::kDataReductionProxyLoFiValueAlwaysOn);
     }
 
     EXPECT_CALL(*config(), IsDataReductionProxy(testing::_, nullptr))
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
index dd55a9e..2ffcf3a 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config.cc
@@ -21,6 +21,7 @@
 #include "components/variations/variations_associated_data.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/load_flags.h"
+#include "net/base/network_change_notifier.h"
 #include "net/base/network_quality.h"
 #include "net/base/network_quality_estimator.h"
 #include "net/proxy/proxy_server.h"
@@ -205,6 +206,8 @@ DataReductionProxyConfig::DataReductionProxyConfig(
       lofi_status_(LOFI_STATUS_TEMPORARILY_OFF) {
   DCHECK(configurator);
   DCHECK(event_creator);
+  if (DataReductionProxyParams::IsLoFiDisabledViaFlags())
+    SetLoFiModeOff();
   // Constructed on the UI thread, but should be checked on the IO thread.
   thread_checker_.DetachFromThread();
 }
@@ -791,11 +794,21 @@ void DataReductionProxyConfig::UpdateLoFiStatusOnMainFrameRequest(
     }
   }
 
-  if (DataReductionProxyParams::IsLoFiEnabledThroughSwitch()) {
+  if (DataReductionProxyParams::IsLoFiAlwaysOnViaFlags()) {
     lofi_status_ = LOFI_STATUS_ACTIVE_FROM_FLAGS;
     return;
   }
 
+  if (DataReductionProxyParams::IsLoFiCellularOnlyViaFlags()) {
+    if (net::NetworkChangeNotifier::IsConnectionCellular(
+            net::NetworkChangeNotifier::GetConnectionType())) {
+      lofi_status_ = LOFI_STATUS_ACTIVE_FROM_FLAGS;
+      return;
+    }
+    lofi_status_ = LOFI_STATUS_TEMPORARILY_OFF;
+    return;
+  }
+
   if (IsIncludedInLoFiControlFieldTrial()) {
     lofi_status_ = IsNetworkQualityProhibitivelySlow(network_quality_estimator)
                        ? LOFI_STATUS_ACTIVE_CONTROL
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_unittest.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_unittest.cc
index 26f726d..b7c7cd1 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_unittest.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_config_unittest.cc
@@ -1158,8 +1158,9 @@ TEST_F(DataReductionProxyConfigTest, LoFiOn) {
   for (size_t i = 0; i < arraysize(tests); ++i) {
     config()->ResetLoFiStatusForTest();
     if (tests[i].lofi_switch_enabled) {
-      base::CommandLine::ForCurrentProcess()->AppendSwitch(
-          data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kDataReductionProxyLoFi,
+          switches::kDataReductionProxyLoFiValueAlwaysOn);
     }
 
     EXPECT_CALL(*config(), IsIncludedInLoFiEnabledFieldTrial())
@@ -1192,8 +1193,9 @@ TEST_F(DataReductionProxyConfigTest, LoFiStatusTransition) {
   for (size_t i = 0; i < arraysize(tests); ++i) {
     config()->ResetLoFiStatusForTest();
     if (tests[i].lofi_switch_enabled) {
-      base::CommandLine::ForCurrentProcess()->AppendSwitch(
-          data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kDataReductionProxyLoFi,
+          switches::kDataReductionProxyLoFiValueAlwaysOn);
     } else {
       EXPECT_CALL(*config(), IsIncludedInLoFiEnabledFieldTrial())
           .WillRepeatedly(testing::Return(true));
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate_unittest.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate_unittest.cc
index c016af2..bc62ac1 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate_unittest.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate_unittest.cc
@@ -226,8 +226,9 @@ TEST_F(DataReductionProxyNetworkDelegateTest, LoFiTransitions) {
 
   for (size_t i = 0; i < arraysize(tests); ++i) {
     if (tests[i].lofi_switch_enabled) {
-      base::CommandLine::ForCurrentProcess()->AppendSwitch(
-          data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kDataReductionProxyLoFi,
+          switches::kDataReductionProxyLoFiValueAlwaysOn);
     }
     config()->SetIncludedInLoFiEnabledFieldTrial(tests[i].auto_lofi_enabled);
     config()->SetNetworkProhibitivelySlow(tests[i].auto_lofi_enabled);
@@ -449,8 +450,9 @@ TEST_F(DataReductionProxyNetworkDelegateTest, NetHistograms) {
     config()->SetNetworkProhibitivelySlow(tests[i].auto_lofi_enabled);
 
     if (tests[i].lofi_enabled_through_switch) {
-      base::CommandLine::ForCurrentProcess()->AppendSwitch(
-          data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+      base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+          switches::kDataReductionProxyLoFi,
+          switches::kDataReductionProxyLoFiValueAlwaysOn);
     }
 
     config()->UpdateLoFiStatusOnMainFrameRequest(false, nullptr);
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 4b26de7..a6b2f69 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
@@ -293,8 +293,9 @@ TEST_F(DataReductionProxyRequestOptionsTest, LoFiOnThroughCommandLineSwitch) {
 
   test_context_->config()->ResetLoFiStatusForTest();
   // Add the LoFi command line switch.
-  base::CommandLine::ForCurrentProcess()->AppendSwitch(
-      data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+  base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+      switches::kDataReductionProxyLoFi,
+      switches::kDataReductionProxyLoFiValueAlwaysOn);
 
   SetHeaderExpectations(kExpectedSession, kExpectedCredentials, std::string(),
                         kClientStr, std::string(), std::string(), "low",
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_service.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_service.cc
index 3b47836..b0eb1993 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_service.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_service.cc
@@ -166,8 +166,12 @@ void DataReductionProxyService::InitializeLoFiPrefs() {
       prefs_->SetInteger(prefs::kLoFiConsecutiveSessionDisables, 0);
       prefs_->SetInteger(prefs::kLoFiImplicitOptOutVersion,
                          lo_fi_implicit_opt_out_version);
-    } else if (prefs_->GetInteger(prefs::kLoFiConsecutiveSessionDisables) >=
-               lo_fi_consecutive_session_disables) {
+    } else if (!DataReductionProxyParams::IsLoFiAlwaysOnViaFlags() &&
+               (prefs_->GetInteger(prefs::kLoFiConsecutiveSessionDisables) >=
+                lo_fi_consecutive_session_disables)) {
+      // If Lo-Fi isn't always on and and the number of
+      // |consecutive_session_disables| has been met, turn Lo-Fi off for this
+      // session.
       SetLoFiModeOff();
     } else if (prefs_->GetInteger(prefs::kLoFiLoadImagesPerSession) <
                lo_fi_user_requests_for_images_per_session) {
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 8866869..b3353a9 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
@@ -196,7 +196,7 @@ void DataReductionProxySettings::SetLoFiShowImageRequested() {
 }
 
 void DataReductionProxySettings::IncrementLoFiUserRequestsForImages() {
-  if (!prefs_)
+  if (!prefs_ || DataReductionProxyParams::IsLoFiAlwaysOnViaFlags())
     return;
   prefs_->SetInteger(prefs::kLoFiLoadImagesPerSession,
                      prefs_->GetInteger(prefs::kLoFiLoadImagesPerSession) + 1);
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 24c108d..e16ae8e 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
@@ -119,9 +119,30 @@ std::string DataReductionProxyParams::GetLoFiFieldTrialName() {
 }
 
 // static
-bool DataReductionProxyParams::IsLoFiEnabledThroughSwitch() {
-  return base::CommandLine::ForCurrentProcess()->HasSwitch(
-      data_reduction_proxy::switches::kEnableDataReductionProxyLoFi);
+bool DataReductionProxyParams::IsLoFiAlwaysOnViaFlags() {
+  const std::string& lo_fi_value =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          data_reduction_proxy::switches::kDataReductionProxyLoFi);
+  return lo_fi_value ==
+         data_reduction_proxy::switches::kDataReductionProxyLoFiValueAlwaysOn;
+}
+
+// static
+bool DataReductionProxyParams::IsLoFiCellularOnlyViaFlags() {
+  const std::string& lo_fi_value =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          data_reduction_proxy::switches::kDataReductionProxyLoFi);
+  return lo_fi_value == data_reduction_proxy::switches::
+                            kDataReductionProxyLoFiValueCellularOnly;
+}
+
+// static
+bool DataReductionProxyParams::IsLoFiDisabledViaFlags() {
+  const std::string& lo_fi_value =
+      base::CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
+          data_reduction_proxy::switches::kDataReductionProxyLoFi);
+  return lo_fi_value ==
+         data_reduction_proxy::switches::kDataReductionProxyLoFiValueDisabled;
 }
 
 //static
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 b4ada80..6a975a2 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
@@ -97,8 +97,16 @@ class DataReductionProxyParams : public DataReductionProxyConfigValues {
       const char* build_fingerprint);
 
   // Returns true if this client has the command line switch to enable Lo-Fi
+  // mode always on.
+  static bool IsLoFiAlwaysOnViaFlags();
+
+  // Returns true if this client has the command line switch to enable Lo-Fi
+  // mode only on cellular connections.
+  static bool IsLoFiCellularOnlyViaFlags();
+
+  // Returns true if this client has the command line switch to disable Lo-Fi
   // mode.
-  static bool IsLoFiEnabledThroughSwitch();
+  static bool IsLoFiDisabledViaFlags();
 
   // Returns true if this client has the command line switch to show
   // interstitials for data reduction proxy bypasses.
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.cc b/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.cc
index fabc575..a62fadf 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.cc
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.cc
@@ -49,6 +49,13 @@ const char kDataReductionProxyWarmupURL[] = "data-reduction-proxy-warmup-url";
 // The origin of the data reduction SSL proxy.
 const char kDataReductionSSLProxy[] = "data-reduction-ssl-proxy";
 
+// The mode for Data Reduction Proxy Lo-Fi. The various modes are always-on,
+// cellular-only, and disabled.
+const char kDataReductionProxyLoFi[] = "data-reduction-proxy-lo-fi";
+const char kDataReductionProxyLoFiValueAlwaysOn[] = "always-on";
+const char kDataReductionProxyLoFiValueCellularOnly[] = "cellular-only";
+const char kDataReductionProxyLoFiValueDisabled[] = "disabled";
+
 // Disables the origin of the data reduction proxy dev.
 const char kDisableDataReductionProxyDev[] =
     "disable-spdy-proxy-dev-auth-origin";
@@ -67,10 +74,6 @@ const char kEnableDataReductionProxy[] = "enable-spdy-proxy-auth";
 // Enable the alternative data reduction proxy.
 const char kEnableDataReductionProxyAlt[] = "enable-data-reduction-proxy-alt";
 
-// Enable Data Reduction Proxy Lo-Fi mode.
-const char kEnableDataReductionProxyLoFi[] =
-    "enable-data-reduction-proxy-lo-fi";
-
 // Enable the data reduction proxy bypass warning.
 const char kEnableDataReductionProxyBypassWarning[] =
     "enable-data-reduction-proxy-bypass-warning";
diff --git a/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h b/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h
index 27fe7c1..8be863d 100644
--- a/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h
+++ b/components/data_reduction_proxy/core/common/data_reduction_proxy_switches.h
@@ -22,12 +22,15 @@ extern const char kDataReductionProxySecureProxyCheckURL[];
 extern const char kDataReductionProxyStartSecureDisabled[];
 extern const char kDataReductionProxyWarmupURL[];
 extern const char kDataReductionSSLProxy[];
+extern const char kDataReductionProxyLoFi[];
+extern const char kDataReductionProxyLoFiValueAlwaysOn[];
+extern const char kDataReductionProxyLoFiValueCellularOnly[];
+extern const char kDataReductionProxyLoFiValueDisabled[];
 extern const char kDisableDataReductionProxyDev[];
 extern const char kEnableDataReductionProxyDev[];
 extern const char kEnableDataReductionProxyCarrierTest[];
 extern const char kEnableDataReductionProxy[];
 extern const char kEnableDataReductionProxyAlt[];
-extern const char kEnableDataReductionProxyLoFi[];
 extern const char kEnableDataReductionProxyBypassWarning[];
 extern const char kClearDataReductionProxyDataSavings[];
 extern const char kEnableDataReductionProxyConfigClient[];
diff --git a/tools/metrics/actions/actions.xml b/tools/metrics/actions/actions.xml
index 2950ed3..370f143 100644
--- a/tools/metrics/actions/actions.xml
+++ b/tools/metrics/actions/actions.xml
@@ -66,6 +66,36 @@ should be able to be added at any place in this file.
   <description>Please enter the description of this user action.</description>
 </action>
 
+<action name="AboutFlags_data-reduction-proxy-lo-fi@1">
+  <owner>bengr@chromium.org</owner>
+  <owner>megjablon@chromium.org</owner>
+  <description>
+    User enabled flag that Forces Data Saver Lo-Fi mode to be always enabled via
+    chrome://flags. The action is emitted once per startup when the flag is
+    active.
+  </description>
+</action>
+
+<action name="AboutFlags_data-reduction-proxy-lo-fi@2">
+  <owner>bengr@chromium.org</owner>
+  <owner>megjablon@chromium.org</owner>
+  <description>
+    User enabled flag that Forces Data Saver Lo-Fi mode to be enabled only on
+    cellular connection via chrome://flags. The action is emitted once per
+    startup when the flag is active.
+  </description>
+</action>
+
+<action name="AboutFlags_data-reduction-proxy-lo-fi@3">
+  <owner>bengr@chromium.org</owner>
+  <owner>megjablon@chromium.org</owner>
+  <description>
+    User enabled flag that Forces Data Saver Lo-Fi mode to be disabled via
+    chrome://flags. The action is emitted once per startup when the flag is
+    active.
+  </description>
+</action>
+
 <action name="AboutFlags_disable-chrome-to-mobile">
   <owner>Please list the metric's owners. Add more owner tags as needed.</owner>
   <description>Please enter the description of this user action.</description>
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index b8c560d..1cb1984 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -58903,6 +58903,7 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="1381746642" label="enable-automatic-password-saving"/>
   <int value="1382500494" label="disable-drive-apps-in-app-list"/>
   <int value="1383591631" label="enable-gesture-typing"/>
+  <int value="1389729816" label="data-reduction-proxy-lo-fi"/>
   <int value="1405459667" label="enable-fast-text-autosizing"/>
   <int value="1407625309"
       label="disable-minimize-on-second-launcher-item-click"/>