Check media permissions (mic/camera) before exposing local addresses to WebRTC.

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 15e8c7d90780a6b38f393b75c5e96f1d96774fa8..98d96a9e916ec659a0ece496567161d190ffb0b6 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -51903,6 +51903,17 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="WebRTC.PeerConnection.IPPermissionStatus"
+    enum="IPPermissionStatus">
+  <owner>guoweis@chromium.org</owner>
+  <summary>
+    Whether the permission to collect the local IP addresses in WebRTC has been
+    requested and/or granted. This is collected in the first time when networks
+    updated event is reported or if never reported, during the destruction phase
+    of a call.
+  </summary>
+</histogram>
+
 <histogram name="WebRTC.PeerConnection.IPv4Interfaces">
   <owner>mallinath@chromium.org</owner>
   <summary>
@@ -51949,6 +51960,15 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <summary>Time to setup a peer to peer call with PeerConnection.</summary>
 </histogram>
 
+<histogram name="WebRTC.PeerConnection.TimeToNetworkUpdated"
+    units="milliseconds">
+  <owner>guoweis@chromium.org</owner>
+  <summary>
+    Time to receive the first SignalNetworksChanged from the request to start
+    updating network in PeerConnection.
+  </summary>
+</histogram>
+
 <histogram name="WebRTC.ReceivedAudioTrackDuration" units="milliseconds">
   <owner>perkj@chromium.org</owner>
   <summary>
@@ -63668,6 +63688,13 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="2" label="SubframeBlocked"/>
 </enum>
 
+<enum name="IPPermissionStatus" type="int">
+  <int value="0" label="Not requested"/>
+  <int value="1" label="Requested but denied"/>
+  <int value="2" label="Requested and granted"/>
+  <int value="3" label="Unknown"/>
+</enum>
+
 <enum name="IPv6ConnectivityStatus" type="int">
   <int value="0" label="Incomplete IPv6 Configuration"/>
   <int value="1" label="Complete IPv6 Configuration"/>