Implement <appview>

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 b460be5edc9779b18d2df3adfe4b534b599449ac..2d0f15dc438f3432d617e22b1650dbf45e676b77 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -38386,7 +38386,7 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="783" label="STREAMSPRIVATE_ABORT"/>
   <int value="784" label="MANAGEMENT_SETLAUNCHTYPE"/>
   <int value="785" label="MANAGEMENT_GENERATEAPPFORLINK"/>
-  <int value="786" label="GUESTVIEWINTERNAL_ALLOCATEINSTANCEID"/>
+  <int value="786" label="DELETED_GUESTVIEWINTERNAL_ALLOCATEINSTANCEID"/>
   <int value="787" label="DELETED_WEBVIEW_NAVIGATE"/>
   <int value="788" label="INPUTMETHODPRIVATE_GETCURRENTINPUTMETHOD"/>
   <int value="789" label="INPUTMETHODPRIVATE_SETCURRENTINPUTMETHOD"/>
@@ -38440,6 +38440,8 @@ Therefore, the affected-histogram name has to have at least one dot in it.
   <int value="836" label="GCDPRIVATE_GETCOMMAND"/>
   <int value="837" label="GCDPRIVATE_CANCELCOMMAND"/>
   <int value="838" label="GCDPRIVATE_GETCOMMANDSLIST"/>
+  <int value="839" label="APPVIEWINTERNAL_ATTACHFRAME"/>
+  <int value="840" label="APPVIEWINTERNAL_DENYREQUEST"/>
 </enum>
 
 <enum name="ExtensionInstallCause" type="int">