chrome/blink: Add functionality for in-product help for media elements.

chrome/browser/android/media_in_product_help_manager.h

+// Copyright 2017 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 CHROME_BROWSER_ANDROID_MEDIA_IN_PRODUCT_HELP_MANAGER_H_
+#define CHROME_BROWSER_ANDROID_MEDIA_IN_PRODUCT_HELP_MANAGER_H_
+
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/web_contents_observer.h"
+#include "services/service_manager/public/cpp/binder_registry.h"
+#include "third_party/WebKit/public/platform/media_in_product_help.mojom.h"
+
+class MediaInProductHelpManagerClient {
+ public:
+  ~MediaInProductHelpManagerClient() {}
+
+  // Updates the position of the InProductHelp widget. |rect_in_frame| provides
+  // the position of the widget in the space of the renderer's main frame.
+  virtual void ShowMediaDownloadInProductHelp(
+      const gfx::Rect& rect_in_frame) = 0;
+
+  // Request to dismiss the InProductHelp widget. This request must be
+  // acknowledged using MediaInProductHelpManager::WidgetDismissed once the
+  // widget is removed.
+  virtual void DismissMediaDownloadInProductHelp() = 0;
+};
+
+class MediaInProductHelpManager : public content::WebContentsObserver {
+ public:
+  MediaInProductHelpManager(content::WebContents* web_contents,
+                            MediaInProductHelpManagerClient* client);
+  ~MediaInProductHelpManager() override;
+
+  // Notifies when the InProductHelp widget requested from the client is
+  // removed.
+  void WidgetDismissed();
+
+  // content::WebContentsObserver implementation.
+  // TODO(khushalsagar): Listen to navigations/process crash to dismiss the
+  // widget in the browser.
+  void RenderFrameCreated(content::RenderFrameHost* render_frame_host) override;
+  void RenderFrameDeleted(content::RenderFrameHost* render_frame_host) override;
+
+ private:
+  class MediaInProductHelp;
+
+  // Methods used by MediaInProductHelpService to plumb notifications from the
+  // renderer.
+  void ShowInProductHelpWidget(content::RenderFrameHost* render_frame_host,
+                               const gfx::Rect& rect_in_main_frame);
+  void HideInProductHelpWidget(content::RenderFrameHost* render_frame_host);
+
+  // Creates the mojo service exposed to the renderer.
+  void CreateInProductHelpService(
+      content::RenderFrameHost* render_frame_host,
+      const service_manager::BindSourceInfo& source_info,
+      blink::mojom::MediaInProductHelpRequest request);
+  void DismissUI();
+
+  content::RenderFrameHost* active_render_frame_host_ = nullptr;
+  MediaInProductHelpManagerClient* client_;

[nyquist, 2017/06/29 02:10:24]

Nit: Could you add a comment describing the ownership / lifetime of this raw
pointer?

[Khushal, 2017/07/07 04:18:14]

Done.

+  base::WeakPtrFactory<MediaInProductHelpManager> weak_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaInProductHelpManager);
+};
+
+#endif  // CHROME_BROWSER_ANDROID_MEDIA_IN_PRODUCT_HELP_MANAGER_H_