bluetooth: Add histograms and logging for connectGATT

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 321071409e9b4fc30000226cbe50dc1614a7b327..3980424b77d9826fd3b875d1a182b43d5e0634a2 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -2752,6 +2752,38 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Bluetooth.Web.ConnectGATT.Outcome"
+    enum="WebBluetoothConnectGATTOutcome">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records the result of a device.connectGATT() call. Used to understand what
+    errors developers are getting so we can target efforts toward the most
+    common ones.
+  </summary>
+</histogram>
+
+<histogram name="Bluetooth.Web.ConnectGATT.TimeFailed" units="seconds">

[Jeffrey Yasskin, 2015/08/12 00:35:45]

https://code.google.com/p/chromium/codesearch/#chromium/src/base/metrics/hist...
says these are both in milliseconds.

[ortuno, 2015/08/12 16:34:04]

Done.

+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records how long it takes for a connection attempt to fail. Use to let
+    developers know how to better wait for and handle connection errors.
+  </summary>
+</histogram>
+
+<histogram name="Bluetooth.Web.ConnectGATT.TimeSuccess" units="milliseconds">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Records how long it takes for a device to successfully connect. Use to let
+    developers know how long it should take to connect to a BLE device.
+  </summary>
+</histogram>
+
 <histogram name="Bluetooth.Web.FunctionCall.Count" enum="WebBluetoothFunction">
   <owner>jyasskin@chromium.org</owner>
   <owner>ortuno@chromium.org</owner>
@@ -71700,6 +71732,19 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="5" label="Policy"/>
 </enum>
 
+<enum name="WebBluetoothConnectGATTOutcome" type="int">
+  <int value="0" label="Success"/>
+  <int value="1" label="Device no longer in range"/>
+  <int value="2" label="Unknown Error"/>
+  <int value="3" label="In Progress"/>
+  <int value="4" label="Failed"/>
+  <int value="5" label="Auth Failed"/>
+  <int value="6" label="Auth Canceled"/>
+  <int value="7" label="Auth Rejected"/>
+  <int value="8" label="Auth Timeout"/>
+  <int value="9" label="Unsupported Device"/>
+</enum>
+
 <enum name="WebBluetoothFunction" type="int">
   <int value="0" label="requestDevice()"/>
   <int value="1" label="connectGATT()"/>