[Policy Experimental] Add policies to allow Cookies and Pop-ups exceptions.

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 22b8a6397ee1fdfee385efff680cc280e7ad8a7f..0f2cf71d200c9b8f68393f4ac220235ab3eb7bd1 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -5989,6 +5989,24 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="ContentSettings.UserCookiesExceptionsUsage"
+    enum="ContentSetting">
+  <owner>huangs@chromium.org</owner>
+  <summary>
+    The policy setting to explicitly enable or disable user exceptions usage to
+    override default cookies settings set by policy.
+  </summary>
+</histogram>
+
+<histogram name="ContentSettings.UserPopupsExceptionsUsage"
+    enum="ContentSetting">
+  <owner>huangs@chromium.org</owner>
+  <summary>
+    The policy setting to explicitly enable or disable user exceptions usage to
+    override default pop-ups settings set by policy.
+  </summary>
+</histogram>
+
 <histogram name="ContextMenu.SaveLinkType" enum="ContextMenuSaveLinkType">
   <owner>qinmin@chromium.org</owner>
   <summary>
@@ -66828,6 +66846,8 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="324" label="Suppress the unsupported OS warning"/>
   <int value="325" label="Enable queries to Quirks Server"/>
   <int value="326" label="Configure the automatic timezone detection method"/>
+  <int value="327" label="User cookies exceptions usage setting"/>
+  <int value="328" label="User pop-ups exceptions usage setting"/>
 </enum>
 
 <enum name="EnterprisePolicyInvalidations" type="int">