Check whether the plugin is disabled in OnIsInternalPluginRegisteredForMimeType().

chrome/browser/plugins/plugin_info_message_filter.cc

Index: chrome/browser/plugins/plugin_info_message_filter.cc
diff --git a/chrome/browser/plugins/plugin_info_message_filter.cc b/chrome/browser/plugins/plugin_info_message_filter.cc
index 634e4bc6dfde697fc60249ae0e4e95af09e57b26..4e8cc473edb3ea2ef06a303bb4efb9528ffb9d7b 100644
--- a/chrome/browser/plugins/plugin_info_message_filter.cc
+++ b/chrome/browser/plugins/plugin_info_message_filter.cc
@@ -62,6 +62,29 @@ bool ShouldUseJavaScriptSettingForPlugin(const WebPluginInfo& plugin) {
   return false;
 }
 
+#if defined(ENABLE_PEPPER_CDMS)
+
+enum PluginAvailabilityStatusForUMA {
+  PLUGIN_AVAILABLE,

[ddorwin, 2014/07/21 17:54:57]

nit: Should these and the histogram values be in a more logical order? DISABLED
seems to come in between, though it might be the least likely.

NOT_REGISTERED is probably the initial state, so it might make sense as first.
Then AVAILABLE then DISABLED?

[xhwang, 2014/07/21 18:16:42]

Done.

+  PLUGIN_NOT_REGISTERED,
+  PLUGIN_DISABLED,
+  PLUGIN_AVAILABILITY_STATUS_MAX
+};
+
+static void SendPluginAvailabilityUMA(const std::string& mime_type,
+                                      PluginAvailabilityStatusForUMA status) {
+#if defined(WIDEVINE_CDM_AVAILABLE)
+  // Only report results for Widevine CDM.
+  if (mime_type != kWidevineCdmPluginMimeType)
+    return;
+
+  UMA_HISTOGRAM_ENUMERATION("Plugin.AvailabilityStatus.WidevineCdm",
+                            status, PLUGIN_AVAILABILITY_STATUS_MAX);
+#endif  // defined(WIDEVINE_CDM_AVAILABLE)
+}
+
+#endif  // defined(ENABLE_PEPPER_CDMS)
+
 }  // namespace
 
 PluginInfoMessageFilter::Context::Context(int render_process_id,
@@ -99,8 +122,8 @@ bool PluginInfoMessageFilter::OnMessageReceived(const IPC::Message& message) {
                                     OnGetPluginInfo)
 #if defined(ENABLE_PEPPER_CDMS)
     IPC_MESSAGE_HANDLER(
-        ChromeViewHostMsg_IsInternalPluginRegisteredForMimeType,
-        OnIsInternalPluginRegisteredForMimeType)
+        ChromeViewHostMsg_IsInternalPluginAvailableForMimeType,
+        OnIsInternalPluginAvailableForMimeType)
 #endif
     IPC_MESSAGE_UNHANDLED(return false)
   IPC_END_MESSAGE_MAP()
@@ -170,29 +193,42 @@ void PluginInfoMessageFilter::PluginsLoaded(
 }
 
 #if defined(ENABLE_PEPPER_CDMS)
-void PluginInfoMessageFilter::OnIsInternalPluginRegisteredForMimeType(
+
+void PluginInfoMessageFilter::OnIsInternalPluginAvailableForMimeType(
     const std::string& mime_type,
-    bool* is_registered,
+    bool* is_available,
     std::vector<base::string16>* additional_param_names,
     std::vector<base::string16>* additional_param_values) {
   std::vector<WebPluginInfo> plugins;
   PluginService::GetInstance()->GetInternalPlugins(&plugins);
+
+  bool is_plugin_disabled = false;
   for (size_t i = 0; i < plugins.size(); ++i) {
+    const WebPluginInfo& plugin = plugins[i];
     const std::vector<content::WebPluginMimeType>& mime_types =
-        plugins[i].mime_types;
+        plugin.mime_types;
     for (size_t j = 0; j < mime_types.size(); ++j) {
       if (mime_types[j].mime_type == mime_type) {
-        *is_registered = true;
+        if (!context_.IsPluginEnabled(plugin)) {
+          is_plugin_disabled = true;
+          break;
+        }
+
+        *is_available = true;
         *additional_param_names = mime_types[j].additional_param_names;
         *additional_param_values = mime_types[j].additional_param_values;
+        SendPluginAvailabilityUMA(mime_type, PLUGIN_AVAILABLE);
         return;
       }
     }
   }
 
-  *is_registered = false;
+  *is_available = false;
+  SendPluginAvailabilityUMA(
+      mime_type, is_plugin_disabled ? PLUGIN_DISABLED : PLUGIN_NOT_REGISTERED);
 }
-#endif
+
+#endif // defined(ENABLE_PEPPER_CDMS)
 
 void PluginInfoMessageFilter::Context::DecidePluginStatus(
     const GetPluginInfo_Params& params,
@@ -403,3 +439,7 @@ void PluginInfoMessageFilter::Context::MaybeGrantAccess(
   }
 }
 
+bool PluginInfoMessageFilter::Context::IsPluginEnabled(
+    const content::WebPluginInfo& plugin) const {
+  return plugin_prefs_->IsPluginEnabled(plugin);
+}