bluetooth: Add histograms and logging for getCharacteristic

content/browser/bluetooth/bluetooth_dispatcher_host.cc

Index: content/browser/bluetooth/bluetooth_dispatcher_host.cc
diff --git a/content/browser/bluetooth/bluetooth_dispatcher_host.cc b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
index 6cad374ff57675ece2d3c8c0eabaa7148a11f094..9d72b2e0af60258a990d80c3c0d7a4e1ca86278a 100644
--- a/content/browser/bluetooth/bluetooth_dispatcher_host.cc
+++ b/content/browser/bluetooth/bluetooth_dispatcher_host.cc
@@ -37,6 +37,8 @@ using UMARequestDeviceOutcome =
 using UMAConnectGATTOutcome = content::BluetoothMetrics::UMAConnectGATTOutcome;
 using UMAGetPrimaryServiceOutcome =
     content::BluetoothMetrics::UMAGetPrimaryServiceOutcome;
+using UMAGetCharacteristicOutcome =
+    content::BluetoothMetrics::UMAGetCharacteristicOutcome;
 using UMAGATTError = content::BluetoothMetrics::UMAGATTError;
 
 namespace {
@@ -388,6 +390,7 @@ void BluetoothDispatcherHost::OnGetCharacteristic(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   BluetoothMetrics::RecordWebBluetoothFunctionCall(
       UMAWebBluetoothFunction::GET_CHARACTERISTIC);
+  BluetoothMetrics::RecordGetCharacteristicCharacteristic(characteristic_uuid);
 
   auto device_iter = service_to_device_.find(service_instance_id);
   // A service_instance_id not in the map implies a hostile renderer
@@ -405,6 +408,9 @@ void BluetoothDispatcherHost::OnGetCharacteristic(
       adapter_->GetDevice(device_iter->second /* device_instance_id */);
 
   if (device == nullptr) {  // See "NETWORK_ERROR Note" above.
+    BluetoothMetrics::RecordGetCharacteristicOutcome(
+        UMAGetCharacteristicOutcome::NO_DEVICE);
+    VLOG(1) << "Bluetooth Device is no longer in range.";

[Jeffrey Yasskin, 2015/08/13 21:32:53]

As discussed over IM, we should drop the VLOGs with constant strings that come
just before a Send(Error(WebBluetoothError)) when the WebBluetoothError is
equivalent to the string.

[ortuno, 2015/08/14 16:23:35]

Done.

     Send(new BluetoothMsg_GetCharacteristicError(
         thread_id, request_id, WebBluetoothError::DeviceNoLongerInRange));
     return;
@@ -415,6 +421,9 @@ void BluetoothDispatcherHost::OnGetCharacteristic(
   device::BluetoothGattService* service =
       device->GetGattService(service_instance_id);
   if (!service) {
+    BluetoothMetrics::RecordGetCharacteristicOutcome(
+        UMAGetCharacteristicOutcome::NO_SERVICE);
+    VLOG(1) << "GATT Service no longer exists.";
     Send(new BluetoothMsg_GetCharacteristicError(
         thread_id, request_id, WebBluetoothError::ServiceNoLongerExists));
     return;
@@ -433,6 +442,8 @@ void BluetoothDispatcherHost::OnGetCharacteristic(
       if (!insert_result.second)
         DCHECK(insert_result.first->second == service_instance_id);
 
+      BluetoothMetrics::RecordGetCharacteristicOutcome(
+          UMAGetCharacteristicOutcome::SUCCESS);
       // TODO(ortuno): Use generated instance ID instead.
       // https://crbug.com/495379
       Send(new BluetoothMsg_GetCharacteristicSuccess(
@@ -440,6 +451,9 @@ void BluetoothDispatcherHost::OnGetCharacteristic(
       return;
     }
   }
+  BluetoothMetrics::RecordGetCharacteristicOutcome(
+      UMAGetCharacteristicOutcome::NOT_FOUND);
+  VLOG(1) << "No GATT Characteristic with UUID: " << characteristic_uuid;

[Jeffrey Yasskin, 2015/08/13 21:32:52]

This one's probably also equivalent to its rejection message, since the caller
has the UUID they passed in.

[ortuno, 2015/08/14 16:23:35]

Removed.

   Send(new BluetoothMsg_GetCharacteristicError(
       thread_id, request_id, WebBluetoothError::CharacteristicNotFound));
 }