[WebsiteSettings] API for permissions bubbles.

chrome/browser/ui/website_settings/permission_bubble_manager.cc

+// Copyright (c) 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/ui/website_settings/permission_bubble_manager.h"
+
+#include "chrome/browser/ui/website_settings/permission_bubble_delegate.h"
+
+void PermissionBubbleManager::AddPermissionBubbleDelegate(
+    PermissionBubbleDelegate* delegate) {
+  RemovePermissionBubbleDelegate(delegate);
+  delegates_.push_back(delegate);
+}
+
+void PermissionBubbleManager::RemovePermissionBubbleDelegate(
+    PermissionBubbleDelegate* delegate) {
+  for (std::vector<PermissionBubbleDelegate*>::const_iterator i =
+           delegates_.begin();
+       i != delegates_.end(); i++) {
+    if (*i == delegate) {
+      delegates_.erase(i);
+      return;
+    }

[groby-ooo-7-16, 2014/01/07 00:31:17]

Let's do this with STL - 
delegates_.erase(std::remove(delegates_.begin(), delegates_.end(), delegate),
delegates_.end())

+  }
+}
+
+PermissionBubbleManager::PermissionBubbleManager(
+    content::WebContents* web_contents)
+  : content::WebContentsObserver(web_contents) {
+}
+
+void PermissionBubbleManager::WebContentsDestroyed(
+    content::WebContents* web_contents) {

[groby-ooo-7-16, 2014/01/07 00:31:17]

I'm aware InfoBarService does this, but I don't think this paranoia is
warranted. What possible case is this covering?

+  // The WebContents is going away; be aggressively paranoid and delete
+  // ourselves lest other parts of the system attempt to add permission bubbles
+  // or use us otherwise during the destruction.
+  web_contents->RemoveUserData(UserDataKey());
+  // That was the equivalent of "delete this". This object is now destroyed;
+  // returning from this function is the only safe thing to do.
+}