Implement ManifestManager to handle manifest in content/

content/browser/manifest/manifest_manager_host.h

+// Copyright 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.
+
+#ifndef CONTENT_RENDERER_MANIFEST_MANIFEST_MANAGER_HOST_H_
+#define CONTENT_RENDERER_MANIFEST_MANIFEST_MANAGER_HOST_H_
+
+#include "base/callback_forward.h"
+#include "base/id_map.h"
+#include "content/public/browser/web_contents_observer.h"
+
+#if defined(COMPILER_GCC)
+namespace BASE_HASH_NAMESPACE {
+template<>
+struct hash<content::RenderFrameHost*> {
+  uint64 operator()(content::RenderFrameHost* ptr) const {
+    return hash<uint64>()(reinterpret_cast<uint64>(ptr));
+  }
+};
+}
+#endif
+
+namespace content {
+
+class RenderFrameHost;
+class WebContents;
+struct Manifest;
+
+// ManifestManagerHost is a helper class that allows callers to get the Manifest
+// associated with a frame. It handles the IPC messaging with the child process.
+// TODO(mlamouri): keep a cached version and a dirty bit here.
+class ManifestManagerHost : public WebContentsObserver {
+ public:
+  explicit ManifestManagerHost(WebContents* web_contents);
+  virtual ~ManifestManagerHost();
+
+  typedef base::Callback<void(const Manifest&)> GetManifestCallback;
+
+  // Calls the given callback with the manifest associated with the
+  // given RenderFrameHost. If the frame has no manifest or if getting it failed
+  // the callback will have an empty manifest.
+  void GetManifest(RenderFrameHost*, const GetManifestCallback&);
+
+  // WebContentsObserver
+  virtual bool OnMessageReceived(const IPC::Message&,
+                                 RenderFrameHost*) OVERRIDE;
+  virtual void RenderFrameDeleted(RenderFrameHost*) OVERRIDE;
+
+ private:
+  typedef IDMap<GetManifestCallback, IDMapOwnPointer> CallbackMap;
+  typedef base::hash_map<RenderFrameHost*, CallbackMap*> FrameCallbackMap;
+
+  void OnRequestManifestResponse(
+      RenderFrameHost*, int request_id, const Manifest&);
+
+  // Returns the CallbackMap associated to the given RenderFrameHost, or null.

[Michael van Ouwerkerk, 2014/09/11 11:03:14]

"associated with"

[mlamouri (slow - plz ping), 2014/09/11 11:11:48]

Done.

+  CallbackMap* GetCallbackMapForFrame(RenderFrameHost*);
+
+  FrameCallbackMap pending_callbacks_;
+
+  DISALLOW_COPY_AND_ASSIGN(ManifestManagerHost);
+};
+
+} // namespace content
+
+#endif // CONTENT_RENDERER_MANIFEST_MANIFEST_MANAGER_HOST_H_