Implement Web Restrictions in WebView.

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 28d90ca0cba04971f8185933e98c46b9baf60fd6..a0800dff12313f3b816bddaf1c4642cca240402c 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -54476,6 +54476,33 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="SupervisedUserContentProvider.ChromeNotStartedRequestTime"
+    units="ms">
+  <owner>aberent@chromium.org</owner>
+  <summary>
+    Time to get the response to requesting whether a URL should be accessible to
+    the supervised user, when Chrome was not previously running.
+  </summary>
+</histogram>
+
+<histogram name="SupervisedUserContentProvider.ChromeStartedRequestTime"
+    units="ms">
+  <owner>aberent@chromium.org</owner>
+  <summary>
+    Time to get the response to requesting whether a URL should be accessible to
+    the supervised user, when Chrome was already running.
+  </summary>
+</histogram>
+
+<histogram name="SupervisedUserContentProvider.RequestTimedOut"
+    enum="BooleanTimedOut">
+  <owner>aberent@chromium.org</owner>
+  <summary>
+    True if a request to find out whether a URL should be accessible to a
+    supervised user timed out.
+  </summary>
+</histogram>
+
 <histogram name="Sync.AppAssociationTime" units="ms">
   <owner>zea@chromium.org</owner>
   <summary>
@@ -69931,7 +69958,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="14" label="Enable Safe Browsing"/>
   <int value="15" label="Enable reporting of usage and crash-related data"/>
   <int value="16" label="Enable saving passwords to the password manager"/>
-  <int value="17" label="Allow users to show passwords in Password Manager"/>
+  <int value="17"
+      label="Allow users to show passwords in Password Manager (deprecated)"/>
   <int value="18" label="Enable AutoFill"/>
   <int value="19" label="Specify a list of disabled plugins"/>
   <int value="20" label="Disable synchronization of data with Google"/>
@@ -70328,13 +70356,14 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="318" label="Configure ARC"/>
   <int value="319"
       label="Allow the auto launched with zero delay kiosk app to control
-             ChromeOS version"/>
+             Google Chrome OS version"/>
   <int value="320" label="Control use of the Web Bluetooth API"/>
   <int value="321" label="Configure the login authentication behavior"/>
   <int value="322" label="Whitelist of USB detachable devices"/>
   <int value="323" label="Allow bluetooth on device"/>
   <int value="324" label="Suppress the unsupported OS warning"/>
-  <int value="325" label="Enable queries to Quirks Server"/>
+  <int value="325"
+      label="Enable queries to Quirks Server for hardware profiles"/>
   <int value="326" label="Configure the automatic timezone detection method"/>
   <int value="327" label="Enable ending processes in Task Manager"/>
   <int value="328"
@@ -70344,6 +70373,7 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="330" label="Set certificate availability for ARC-apps"/>
   <int value="331" label="Define domains allowed to access Google Apps"/>
   <int value="332" label="Enable PAC https:// URL stripping"/>
+  <int value="333" label="Set an external source of URL restrictions"/>
 </enum>
 
 <enum name="EnterprisePolicyInvalidations" type="int">