Add UMA for the new generic permisison class

chrome/browser/content_settings/permission_context_base.h

Index: chrome/browser/content_settings/permission_context_base.h
diff --git a/chrome/browser/content_settings/permission_context_base.h b/chrome/browser/content_settings/permission_context_base.h
index 76bbc91137b615688b3c4b4b1e2e4d802138c25d..871ea9300424270972f3d7e706dcd387faec69c7 100644
--- a/chrome/browser/content_settings/permission_context_base.h
+++ b/chrome/browser/content_settings/permission_context_base.h
@@ -22,6 +22,17 @@ namespace content {
 class WebContents;
 }
 
+// Enum for UMA purposes, make sure you update histograms.xml if you
+// add new pemissions.
+enum PermissionType {
+  PERMISSION_UNKNOWN,
+  PERMISSION_MIDI_SYSEX,
+  PERMISSION_PUSH_MESSAGING,
+
+  // Always keep this at the end.
+  PERMISSION_NUM,
+};
+
 typedef base::Callback<void(bool)> BrowserPermissionCallback;
 
 // This base class contains common operations for granting permissions.
@@ -79,6 +90,7 @@ class PermissionContextBase : public KeyedService {
                          const GURL& requesting_origin,
                          const GURL& embedder_origin,
                          const BrowserPermissionCallback& callback,
+                         bool persist,
                          bool allowed);
 
   void NotifyPermissionSet(const PermissionRequestID& id,
@@ -98,6 +110,7 @@ class PermissionContextBase : public KeyedService {
   PermissionQueueController* GetQueueController();
 
  private:
+  static PermissionType SettingToPermission(ContentSettingsType permission);

[Bernhard Bauer, 2014/07/08 12:54:52]

If this method is static and private, do you need it as a class method in the
header, or could it be in an anonymous namespace in the .cc file?

[Miguel Garcia, 2014/07/08 14:14:20]

Sure, it does not need to be a method, it cans just be an anonymous function

   void UpdateContentSetting(
       const GURL& requesting_origin,
       const GURL& embedder_origin,