Content Settings: Add RevocationObserver to measure when permissions are revoked

chrome/browser/permissions/permission_manager.cc

Index: chrome/browser/permissions/permission_manager.cc
diff --git a/chrome/browser/permissions/permission_manager.cc b/chrome/browser/permissions/permission_manager.cc
index c1a719a45241bd34562014df15d8fad512357426..ed4d423e1469251d014cc8cff07af81457cda7a2 100644
--- a/chrome/browser/permissions/permission_manager.cc
+++ b/chrome/browser/permissions/permission_manager.cc
@@ -12,6 +12,8 @@
 #include "chrome/browser/permissions/permission_context.h"
 #include "chrome/browser/permissions/permission_context_base.h"
 #include "chrome/browser/permissions/permission_request_id.h"
+#include "chrome/browser/permissions/permission_uma_util.h"
+#include "chrome/browser/permissions/permission_util.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/tab_contents/tab_util.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
@@ -198,12 +200,16 @@ struct PermissionManager::Subscription {
 PermissionManager::PermissionManager(Profile* profile)
     : profile_(profile),
       weak_ptr_factory_(this) {
+  HostContentSettingsMapFactory::GetForProfile(profile_)->AddRevocationObserver(
+      this);
 }
 
 PermissionManager::~PermissionManager() {
+  HostContentSettingsMap* map =
+      HostContentSettingsMapFactory::GetForProfile(profile_);
+  map->RemoveRevocationObserver(this);
   if (!subscriptions_.IsEmpty())
-    HostContentSettingsMapFactory::GetForProfile(profile_)
-        ->RemoveObserver(this);
+    map->RemoveObserver(this);
 }
 
 int PermissionManager::RequestPermission(
@@ -429,3 +435,14 @@ void PermissionManager::OnContentSettingChanged(
   for (const auto& callback : callbacks)
     callback.Run();
 }
+
+void PermissionManager::OnContentSettingRevoked(
+    const GURL& primary_url,
+    const GURL& secondary_url,
+    ContentSettingsType content_type,
+    std::string resource_identifier) {
+  PermissionType permission_type;
+  if (PermissionUtil::GetPermissionType(content_type, &permission_type)) {

[raymes, 2016/03/17 02:05:43]

nit: no {}

[tsergeant, 2016/03/17 06:25:40]

Done.

+    PermissionUmaUtil::PermissionRevoked(permission_type, primary_url);

[kcarattini, 2016/03/17 02:51:22]

Is going to change how often revocation is reported? How about adding a comment
on the RAPPOR metric with the date of the reporting change release, that way we
won't mistake it for a change in user behaviour?

[tsergeant, 2016/03/17 06:25:40]

Good idea, done.

+  }
+}