Adds special support to the device manager for keyboards devices.

ui/events/device_data_manager.cc

Index: ui/events/device_data_manager.cc
diff --git a/ui/events/device_data_manager.cc b/ui/events/device_data_manager.cc
index d255b871abc80b10082d7408e92e25deafc7cb9a..6c5e6eba08641a1455aed89fbda0a08427583c42 100644
--- a/ui/events/device_data_manager.cc
+++ b/ui/events/device_data_manager.cc
@@ -13,6 +13,20 @@
 
 namespace ui {
 
+namespace {
+
+bool TouchscreenEquals(const ui::TouchscreenDevice& a,
+    const ui::TouchscreenDevice& b) {
+  return a.id == b.id;
+}
+
+bool KeyboardEquals(const ui::KeyboardDevice& a,
+    const ui::KeyboardDevice& b) {
+  return a.id == b.id;
+}

[flackr, 2014/10/06 18:31:11]

Can this not be done with a single InputDeviceEquals(const ui::InputDevice& a,
const ui::InputDevice& b)?

[rsadam, 2014/10/06 19:38:01]

Done.

+
+}  // namespace
+
 // static
 DeviceDataManager* DeviceDataManager::instance_ = NULL;
 
@@ -111,11 +125,28 @@ int64_t DeviceDataManager::GetDisplayForTouchDevice(int touch_device_id) const {
 
 void DeviceDataManager::OnTouchscreenDevicesUpdated(
     const std::vector<TouchscreenDevice>& devices) {
+  if (devices.size() == touchscreen_devices_.size() &&
+      std::equal(devices.begin(), devices.end(),
+          touchscreen_devices_.begin(), TouchscreenEquals)) {
+    return;
+  }
   touchscreen_devices_ = devices;
+  FOR_EACH_OBSERVER(InputDeviceEventObserver,
+                  observers_,
+                  OnTouchscreenDeviceConfigurationChanged());
+}
 
+void DeviceDataManager::OnKeyboardDevicesUpdated(
+    const std::vector<KeyboardDevice>& devices) {
+  if (devices.size() == keyboard_devices_.size() &&
+      std::equal(devices.begin(), devices.end(),
+          keyboard_devices_.begin(), KeyboardEquals)) {
+    return;
+  }
+  keyboard_devices_ = devices;
   FOR_EACH_OBSERVER(InputDeviceEventObserver,
-                    observers_,
-                    OnInputDeviceConfigurationChanged());
+                  observers_,
+                  OnKeyboardDeviceConfigurationChanged());
 }
 
 void DeviceDataManager::AddObserver(InputDeviceEventObserver* observer) {