Linux native notifications: Add server capabilities metrics

chrome/browser/notifications/notification_platform_bridge_linux.cc

Index: chrome/browser/notifications/notification_platform_bridge_linux.cc
diff --git a/chrome/browser/notifications/notification_platform_bridge_linux.cc b/chrome/browser/notifications/notification_platform_bridge_linux.cc
index cf71db8869d0a8a1c7c5f89085a7fd8338243d6c..080a2f6162bc0de87ab5c8911771071c0d4051bf 100644
--- a/chrome/browser/notifications/notification_platform_bridge_linux.cc
+++ b/chrome/browser/notifications/notification_platform_bridge_linux.cc
@@ -8,6 +8,7 @@
 
 #include "base/barrier_closure.h"
 #include "base/files/file_util.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/strings/nullable_string16.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
@@ -278,11 +279,55 @@ class NotificationPlatformBridgeLinuxImpl
     notification_proxy_ =
         bus_->GetObjectProxy(kFreedesktopNotificationsName,
                              dbus::ObjectPath(kFreedesktopNotificationsPath));
+    UMA_HISTOGRAM_BOOLEAN("org.Freedesktop.Notifications",
+                          !!notification_proxy_);

[Mark P, 2017/05/01 22:07:01]

drive-by nit: I find "!!" hard to read.

[Tom (Use chromium acct), 2017/05/01 22:35:01]

Done.

     if (!notification_proxy_) {
       OnConnectionInitializationFinishedOnTaskRunner(false);
       return;
     }
 
+    dbus::MethodCall get_capabilities_call(kFreedesktopNotificationsName,
+                                           "GetCapabilities");
+    std::unique_ptr<dbus::Response> capabilities_response =
+        notification_proxy_->CallMethodAndBlock(
+            &get_capabilities_call, dbus::ObjectProxy::TIMEOUT_USE_DEFAULT);
+    if (capabilities_response) {
+      dbus::MessageReader reader(capabilities_response.get());
+      std::vector<std::string> capabilities;
+      reader.PopArrayOfStrings(&capabilities);
+      for (const std::string& capability : capabilities)
+        capabilities_.insert(capability);
+    }
+    // Histogram macros must be called with the same name for each
+    // callsite, so we can't roll the below into a nice loop.
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.action-icons",
+        capabilities_.count("action-icons"));
+    UMA_HISTOGRAM_BOOLEAN("org.Freedesktop.Notifications.Capabilities.actions",
+                          capabilities_.count("actions"));
+    UMA_HISTOGRAM_BOOLEAN("org.Freedesktop.Notifications.Capabilities.body",
+                          capabilities_.count("body"));
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.body-hyperlinks",
+        capabilities_.count("body-hyperlinks"));
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.body-images",
+        capabilities_.count("body-images"));
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.body-markup",
+        capabilities_.count("body-markup"));
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.icon-multi",
+        capabilities_.count("icon-multi"));
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.icon-static",
+        capabilities_.count("icon-static"));
+    UMA_HISTOGRAM_BOOLEAN(
+        "org.Freedesktop.Notifications.Capabilities.persistence",
+        capabilities_.count("persistence"));
+    UMA_HISTOGRAM_BOOLEAN("org.Freedesktop.Notifications.Capabilities.sound",
+                          capabilities_.count("sound"));
+
     connected_signals_barrier_ = base::BarrierClosure(
         2, base::Bind(&NotificationPlatformBridgeLinuxImpl::
                           OnConnectionInitializationFinishedOnTaskRunner,
@@ -547,6 +592,8 @@ class NotificationPlatformBridgeLinuxImpl
   // indicates the connection is ready to use.
   void OnConnectionInitializationFinishedOnUiThread(bool success) {
     DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
+    UMA_HISTOGRAM_BOOLEAN("Linux.NativeNotifications.UsingNativeNotifications",
+                          success);
     connected_ = success;
     for (auto& callback : on_connected_callbacks_)
       std::move(callback).Run(success);
@@ -595,6 +642,8 @@ class NotificationPlatformBridgeLinuxImpl
 
   dbus::ObjectProxy* notification_proxy_ = nullptr;
 
+  std::unordered_set<std::string> capabilities_;
+
   base::Closure connected_signals_barrier_;
 
   // A std::set<std::unique_ptr<T>> doesn't work well because