tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 21ca627e2e6d2cef03d2b79865b805b5dae8340d..77f68acf817d356f1f441141977b2df20cf0c596 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -5139,6 +5139,54 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Bluetooth.Web.GetDescriptor.Descriptor"
+    enum="GATTDescriptorHash">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records the UUIDs used when getting a descriptor. The recorded value is a
+    31-bit hash of the UUID. Used to know what types of descriptors to target
+    when building libraries that use the Web Bluetooth API.
+  </summary>
+</histogram>
+
+<histogram name="Bluetooth.Web.GetDescriptor.Outcome"
+    enum="WebBluetoothGetDescriptorOutcome">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records the outcome of a call to getDescriptor(). Used to understand what
+    errors developers are getting so we can target efforts toward the most
+    common ones.
+  </summary>
+</histogram>
+
+<histogram name="Bluetooth.Web.GetDescriptors.Descriptor"

[Ilya Sherman, 2017/02/11 00:18:27]

What's the motivation for separating out getDescriptor() from getDescriptors()
calls?  Are they likely to be used in different contexts / have different
behavior?

[dougt, 2017/02/11 00:56:09]

Following what characteristics did. I suspect it's to determine which call path
is more frequently being used.  Gio, do you have any thoughts?

[ortuno, 2017/02/13 00:34:15]

Also getDescriptor() has a required parameter whereas getDescriptors() has a
optional parameter only. It's useful to know how often getDescriptors() is
called without that parameter.

+    enum="GATTDescriptorHash">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records the UUIDs used when getting descriptors. The recorded value is a
+    31-bit hash of the UUID. Used to know what types of descriptors to target
+    when building libraries that use the Web Bluetooth API.
+  </summary>
+</histogram>
+
+<histogram name="Bluetooth.Web.GetDescriptors.Outcome"
+    enum="WebBluetoothGetDescriptorOutcome">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records the outcome of a call to getDescriptors(). Used to understand what
+    errors developers are getting so we can target efforts toward the most
+    common ones.
+  </summary>
+</histogram>
+
 <histogram name="Bluetooth.Web.GetPrimaryService.Outcome"
     enum="WebBluetoothGetPrimaryServiceOutcome">
   <owner>jyasskin@chromium.org</owner>
@@ -91408,7 +91456,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
 </enum>
 
 <enum name="GATTCharacteristicHash" type="int">
-<!-- Hash values can be produced using tool: bluetooth_metrics_hash (Only built via GN, not GYP) -->
+<!-- Hash values can be produced using tool: bluetooth_metrics_hash -->
 
   <int value="1615384" label="alert_notification_control_point"/>
   <int value="4531384" label="date_of_birth"/>
@@ -91761,8 +91809,52 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="2140490935" label="gatt.service_changed"/>
 </enum>
 
+<enum name="GATTDescriptorHash" type="int">
+<!-- Hash values can be produced using tool: bluetooth_metrics_hash -->
+
+  <int value="34360078"
+      label="Environmental Sensing Configuration;
+             0000290b-0000-1000-8000-00805f9b34fb"/>
+  <int value="212028968"
+      label="Value Trigger Setting; 0000290a-0000-1000-8000-00805f9b34fb"/>
+  <int value="434053918"
+      label="Valid Range; 00002906-0000-1000-8000-00805f9b34fb"/>
+  <int value="475200414"
+      label="Characteristic Aggregate Format;
+             00002905-0000-1000-8000-00805f9b34fb"/>
+  <int value="1007170263"
+      label="Report Reference; 00002908-0000-1000-8000-00805f9b34fb"/>
+  <int value="1035573722"
+      label="External Report Reference; 00002907-0000-1000-8000-00805f9b34fb"/>
+  <int value="1113090825"
+      label="Characteristic Presentation Format;
+             00002904-0000-1000-8000-00805f9b34fb"/>
+  <int value="1130337922"
+      label="Number of Digitals; 00002909-0000-1000-8000-00805f9b34fb"/>
+  <int value="1201129743"
+      label="Client Characteristic Configuration;
+             00002902-0000-1000-8000-00805f9b34fb"/>
+  <int value="1208669602"
+      label="Environmental Sensing Trigger Setting;
+             0000290d-0000-1000-8000-00805f9b34fb"/>
+  <int value="1322265676"
+      label="Server Characteristic Configuration;
+             00002903-0000-1000-8000-00805f9b34fb"/>
+  <int value="1383133454"
+      label="Environmental Sensing Measurement;
+             0000290c-0000-1000-8000-00805f9b34fb"/>
+  <int value="1406247203"
+      label="Time Trigger Setting; 0000290e-0000-1000-8000-00805f9b34fb"/>
+  <int value="1504592234"
+      label="Characteristic User Description;
+             00002901-0000-1000-8000-00805f9b34fb"/>
+  <int value="1876461392"
+      label="Characteristic Extended Properties;
+             00002900-0000-1000-8000-00805f9b34fb"/>
+</enum>
+
 <enum name="GATTServiceHash" type="int">
-<!-- Hash values can be produced using tool: bluetooth_metrics_hash (Only built via GN, not GYP) -->
+<!-- Hash values can be produced using tool: bluetooth_metrics_hash -->
 
   <int value="7464675" label="pulse_oximeter"/>
   <int value="26695985" label="fe20"/>
@@ -109609,6 +109701,10 @@ value.
   <int value="8" label="RemoteGATTServer.disconnect()"/>
   <int value="9" label="RemoteGATTService.getCharacteristics()"/>
   <int value="10" label="RemoteGATTServer.getPrimaryServices()"/>
+  <int value="11" label="RemoteGATTDescriptor.readValue()"/>
+  <int value="12" label="RemoteGATTDescriptor.writeValue()"/>
+  <int value="13" label="RemoteGATTCharacteristic.getDescriptor()"/>
+  <int value="14" label="RemoteGATTCharacteristic.getDescriptors()"/>
 </enum>
 
 <enum name="WebBluetoothGATTOperationOutcome" type="int">
@@ -109637,6 +109733,16 @@ value.
   <int value="5" label="No characteristics"/>
 </enum>
 
+<enum name="WebBluetoothGetDescriptorOutcome" type="int">
+  <int value="0" label="Success"/>
+  <int value="1" label="No device"/>
+  <int value="2" label="No service"/>
+  <int value="3" label="No characteristic"/>
+  <int value="4" label="Not found"/>
+  <int value="5" label="Blocklisted"/>
+  <int value="6" label="No descriptors"/>
+</enum>
+
 <enum name="WebBluetoothGetPrimaryServiceOutcome" type="int">
   <int value="0" label="Success"/>
   <int value="1" label="Device no longer in range."/>