Add flag to override Effective Connection Type

chrome/browser/about_flags.cc

Index: chrome/browser/about_flags.cc
diff --git a/chrome/browser/about_flags.cc b/chrome/browser/about_flags.cc
index 0fd1b2383050750f22955e9869957166f861f770..2ec43412083deb08707536d2dcfa0929457a54d4 100644
--- a/chrome/browser/about_flags.cc
+++ b/chrome/browser/about_flags.cc
@@ -85,6 +85,7 @@
 #include "media/media_features.h"
 #include "media/midi/midi_switches.h"
 #include "net/cert/cert_verify_proc_android.h"
+#include "net/nqe/effective_connection_type.h"
 #include "ppapi/features/features.h"
 #include "printing/features/features.h"
 #include "services/device/public/cpp/device_features.h"
@@ -715,6 +716,36 @@ const FeatureEntry::Choice kAutoplayPolicyChoices[] = {
 #endif
 };
 
+const FeatureEntry::Choice kForceEffectiveConnectionTypeChoices[] = {
+    {flags_ui::kGenericExperimentChoiceDefault, "", ""},
+    {flag_descriptions::kEffectiveConnectionTypeUnknownDescription,
+     switches::kForceEffectiveConnectionType,
+     net::kEffectiveConnectionTypeUnknown},
+    {flag_descriptions::kEffectiveConnectionTypeOfflineDescription,
+     switches::kForceEffectiveConnectionType,
+     net::kEffectiveConnectionTypeOffline},
+    {flag_descriptions::kEffectiveConnectionTypeSlow2GDescription,
+     switches::kForceEffectiveConnectionType,
+     net::kEffectiveConnectionTypeSlow2G},
+    {flag_descriptions::kEffectiveConnectionType2GDescription,
+     switches::kForceEffectiveConnectionType, net::kEffectiveConnectionType2G},
+    {flag_descriptions::kEffectiveConnectionType3GDescription,
+     switches::kForceEffectiveConnectionType, net::kEffectiveConnectionType3G},
+    {flag_descriptions::kEffectiveConnectionType4GDescription,
+     switches::kForceEffectiveConnectionType, net::kEffectiveConnectionType4G},
+};
+
+// Ensure that all effective connection types returned by Network Quality
+// Estimator (NQE) are also exposed via flags.
+static_assert(net::EFFECTIVE_CONNECTION_TYPE_LAST + 1 ==
+                  arraysize(kForceEffectiveConnectionTypeChoices),
+              "ECT enum value is not handled.");
+static_assert(net::EFFECTIVE_CONNECTION_TYPE_UNKNOWN == 0,
+              "ECT enum value is not handled.");
+static_assert(net::EFFECTIVE_CONNECTION_TYPE_4G + 1 ==
+                  net::EFFECTIVE_CONNECTION_TYPE_LAST,
+              "ECT enum value is not handled.");
+
 const FeatureEntry::FeatureParam kNoStatePrefetchEnabled[] = {
     {prerender::kNoStatePrefetchFeatureModeParameterName,
      prerender::kNoStatePrefetchFeatureModeParameterPrefetch}};
@@ -2782,6 +2813,11 @@ const FeatureEntry kFeatureEntries[] = {
      flag_descriptions::kAutoplayPolicyDescription, kOsAll,
      MULTI_VALUE_TYPE(kAutoplayPolicyChoices)},
 
+    {"force-effective-connection-type",
+     flag_descriptions::kForceEffectiveConnectionTypeName,
+     flag_descriptions::kForceEffectiveConnectionTypeDescription, kOsAll,
+     MULTI_VALUE_TYPE(kForceEffectiveConnectionTypeChoices)},
+
     {"enable-heap-profiling", flag_descriptions::kEnableHeapProfilingName,
      flag_descriptions::kEnableHeapProfilingDescription, kOsAll,
      MULTI_VALUE_TYPE(kEnableHeapProfilingChoices)},