Implement WebBluetooth descriptor.writeValue()

content/browser/bluetooth/bluetooth_metrics.h

Index: content/browser/bluetooth/bluetooth_metrics.h
diff --git a/content/browser/bluetooth/bluetooth_metrics.h b/content/browser/bluetooth/bluetooth_metrics.h
index 65ad7b4f6160f3ea14802189c428c7ba330c7e80..55aac46cf83719c64b30920274b1e4721fc4baa1 100644
--- a/content/browser/bluetooth/bluetooth_metrics.h
+++ b/content/browser/bluetooth/bluetooth_metrics.h
@@ -36,6 +36,7 @@ enum class UMAWebBluetoothFunction {
   SERVICE_GET_CHARACTERISTICS = 9,
   GET_PRIMARY_SERVICES = 10,
   DESCRIPTOR_READ_VALUE = 11,
+  DESCRIPTOR_WRITE_VALUE = 12,

[ortuno, 2017/01/31 19:50:09]

Add this to histograms.xml

[dougt, 2017/01/31 20:59:16]

This change is in https://codereview.chromium.org/2662433003 which has a lgtm. 
Do you want me to move that change to this CL?

[ortuno, 2017/02/01 00:01:58]

Not really. This changes the WebBluetoothFunction enum in histograms.xml[1]
(which now that I see is missing all the descriptors enums.) The change in the
follow up is for the output of the descriptor.writeValue().

[1]
https://cs.chromium.org/chromium/src/tools/metrics/histograms/histograms.xml?...

   // NOTE: Add new actions immediately above this line. Make sure to update
   // the enum list in tools/metrics/histograms/histograms.xml accordingly.
   COUNT
@@ -239,6 +240,7 @@ enum class UMAGATTOperation {
   CHARACTERISTIC_WRITE,
   START_NOTIFICATIONS,
   DESCRIPTOR_READ,
+  DESCRIPTOR_WRITE,
   // Note: Add new GATT Operations immediately above this line.
   COUNT
 };