bluetooth: Fix layering violation in BluetoothChooserController

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 48e53f0b242d9ad8d9fa3e18d69c87245d86340c..d409b640eca5108564886b2fbdbad3ea7b64b029 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -4431,6 +4431,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="Bluetooth.Web.ChooserInteraction"
+    enum="WebBluetoothChooserInteractionType">
+  <owner>jyasskin@chromium.org</owner>
+  <owner>ortuno@chromium.org</owner>
+  <owner>scheib@chromium.org</owner>
+  <summary>
+    Counts how many times users interact with a regular chooser vs. an invalid
+    chooser. (A chooser is invalid when it's event handler becomes null.)
+  </summary>
+</histogram>
+
 <histogram name="Bluetooth.Web.ConnectGATT.Outcome"
     enum="WebBluetoothConnectGATTOutcome">
   <owner>jyasskin@chromium.org</owner>
@@ -96845,6 +96856,11 @@ To add a new entry, add it with any value and run test to compute valid value.
   <int value="4" label="Session, Warmup"/>
 </enum>
 
+<enum name="WebBluetoothChooserInteractionType" type="int">

[Ilya Sherman, 2016/08/26 00:17:44]

nit: I'd name this "BooleanInvalid"

[ortuno, 2016/08/26 16:14:36]

Done.

+  <int value="0" label="Valid"/>
+  <int value="1" label="Invalid"/>
+</enum>
+
 <enum name="WebBluetoothConnectGATTOutcome" type="int">
   <int value="0" label="Success"/>
   <int value="1" label="Device no longer in range"/>