Send WM_DEVICECHANGE message through SystemMonitor

WM_DEVICECHANGE is sent when there's been a change to devices or the computer;
specifically when a USB device is connected or disconnected. This is intended
for use in support of Gamepads for more performant polling and
connect/disconnect testing. Currently only on Windows, though seems reasonable
to add for other platforms in the future.

BUG=79050


Review URL: http://codereview.chromium.org/8523021

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@109960 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 46 insertions, 1 deletions

diff --git a/base/system_monitor/system_monitor_unittest.cc b/base/system_monitor/system_monitor_unittest.cc
index f4a4e73..1d5d6af 100644
--- a/base/system_monitor/system_monitor_unittest.cc
+++ b/base/system_monitor/system_monitor_unittest.cc
@@ -55,7 +55,7 @@ TEST(SystemMonitor, PowerNotifications) {
   SystemMonitor system_monitor;
   PowerTest test[kObservers];
   for (int index = 0; index < kObservers; ++index)
-    system_monitor.AddObserver(&test[index]);
+    system_monitor.AddPowerObserver(&test[index]);
 
   // Send a bunch of power changes.  Since the battery power hasn't
   // actually changed, we shouldn't get notifications.
@@ -90,4 +90,49 @@ TEST(SystemMonitor, PowerNotifications) {
   EXPECT_EQ(test[0].resumes(), 1);
 }
 
+class DevicesChangedTest : public SystemMonitor::DevicesChangedObserver {
+ public:
+  DevicesChangedTest()
+      : changes_(0) {
+  }
+
+  // DevicesChangedObserver callbacks.
+  virtual void OnDevicesChanged() OVERRIDE {
+    changes_++;
+  }
+
+  // Test status counts.
+  int changes() const { return changes_; }
+
+ private:
+  int changes_;  // Count of OnDevicesChanged notifications.
+
+  DISALLOW_COPY_AND_ASSIGN(DevicesChangedTest);
+};
+
+TEST(SystemMonitor, DeviceChangeNotifications) {
+  const int kObservers = 5;
+
+  // Initialize a message loop for this to run on.
+  MessageLoop loop;
+
+#if defined(OS_MACOSX)
+  SystemMonitor::AllocateSystemIOPorts();
+#endif
+
+  SystemMonitor system_monitor;
+  DevicesChangedTest test[kObservers];
+  for (int index = 0; index < kObservers; ++index)
+    system_monitor.AddDevicesChangedObserver(&test[index]);
+
+  system_monitor.ProcessDevicesChanged();
+  loop.RunAllPending();
+  EXPECT_EQ(1, test[0].changes());
+
+  system_monitor.ProcessDevicesChanged();
+  system_monitor.ProcessDevicesChanged();
+  loop.RunAllPending();
+  EXPECT_EQ(3, test[0].changes());
+}
+
 }  // namespace base