Add the IDL and stub implementation for the chrome.autofillPrivate API.

extensions/browser/extension_function_histogram_value.h

Index: extensions/browser/extension_function_histogram_value.h
diff --git a/extensions/browser/extension_function_histogram_value.h b/extensions/browser/extension_function_histogram_value.h
index ed35bc032ba4aaf86f9df6e0f28c7cbc57febbe1..bd40f74cac94706ba6a348041ced8e57ab09a8c3 100644
--- a/extensions/browser/extension_function_histogram_value.h
+++ b/extensions/browser/extension_function_histogram_value.h
@@ -1069,6 +1069,12 @@ enum HistogramValue {
   DEVELOPERPRIVATE_SHOWPATH,
   FILEMANAGERPRIVATE_ADDPROVIDEDFILESYSTEM,
   FILEMANAGERPRIVATE_CONFIGUREPROVIDEDFILESYSTEM,
+  AUTOFILLPRIVATE_SAVEADDRESS,
+  AUTOFILLPRIVATE_GETADDRESSCOMPONENTS,
+  AUTOFILLPRIVATE_SAVECREDITCARD,
+  AUTOFILLPRIVATE_REMOVEENTRY,
+  AUTOFILLPRIVATE_VALIDATEPHONENUMBERS,
+  AUTOFILLPRIVATE_MASKCREDITCARD,
   // Last entry: Add new entries above and ensure to update
   // tools/metrics/histograms/histograms.xml.
   ENUM_BOUNDARY