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

chrome/browser/android/media_in_product_help_manager.cc

+// 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.
+
+#include "chrome/browser/android/media_in_product_help_manager.h"
+
+#include "base/memory/ptr_util.h"
+#include "base/optional.h"
+#include "content/public/browser/navigation_handle.h"
+#include "content/public/browser/render_frame_host.h"
+#include "content/public/browser/render_widget_host_view.h"
+#include "mojo/public/cpp/bindings/strong_binding.h"
+#include "services/service_manager/public/cpp/bind_source_info.h"
+#include "services/service_manager/public/cpp/interface_provider.h"
+
+// This class is created and owned by the MediaInProductHelpManager.
+class MediaInProductHelpManager::MediaInProductHelp
+    : public blink::mojom::MediaInProductHelp {
+ public:
+  MediaInProductHelp(content::RenderFrameHost* render_frame_host,
+                     MediaInProductHelpManager* manager,
+                     blink::mojom::MediaInProductHelpRequest request)
+      : render_frame_host_(render_frame_host),
+        manager_(manager),
+        binding_(this, std::move(request)) {
+    DCHECK(render_frame_host_);
+    DCHECK(manager_);
+
+    binding_.set_connection_error_handler(
+        base::BindOnce(&MediaInProductHelpManager::OnConnectionError,
+                       base::Unretained(manager_)));
+  }
+  ~MediaInProductHelp() override = default;
+
+  // blink::mojom::MediaPromoUI implementation.
+  void ShowInProductHelpWidget(const gfx::Rect& rect) override {
+    manager_->ShowInProductHelpWidget(rect);
+  }
+
+  content::RenderFrameHost* render_frame_host() const {
+    return render_frame_host_;
+  }
+
+ private:
+  // The |manager_| and |render_frame_host_| outlive this class.
+  content::RenderFrameHost* render_frame_host_;
+  MediaInProductHelpManager* manager_;
+  mojo::Binding<blink::mojom::MediaInProductHelp> binding_;
+};

[Sam McNally, 2017/07/07 05:22:58]

DISALLOW_COPY_AND_ASSIGN

+
+MediaInProductHelpManager::MediaInProductHelpManager(
+    content::WebContents* web_contents,
+    MediaInProductHelpManagerClient* client)
+    : WebContentsObserver(web_contents), client_(client), weak_factory_(this) {
+  DCHECK(client_);
+}
+
+MediaInProductHelpManager::~MediaInProductHelpManager() {
+  if (media_in_product_help_) {
+    client_->DismissMediaDownloadInProductHelp();
+  }
+}
+
+void MediaInProductHelpManager::WidgetDismissed() {
+  DCHECK(media_in_product_help_);
+  media_in_product_help_.reset();
+}
+
+void MediaInProductHelpManager::RenderFrameCreated(
+    content::RenderFrameHost* render_frame_host) {
+  // Register the service for the renderer to request showing the UI.
+  render_frame_host->GetInterfaceRegistry()->AddInterface(
+      base::Bind(&MediaInProductHelpManager::CreateInProductHelpService,
+                 weak_factory_.GetWeakPtr(), render_frame_host));
+}
+
+void MediaInProductHelpManager::RenderFrameDeleted(
+    content::RenderFrameHost* render_frame_host) {
+  if (media_in_product_help_ &&
+      media_in_product_help_->render_frame_host() == render_frame_host) {
+    client_->DismissMediaDownloadInProductHelp();
+  }
+}
+
+void MediaInProductHelpManager::CreateInProductHelpService(
+    content::RenderFrameHost* render_frame_host,
+    const service_manager::BindSourceInfo& source_info,
+    blink::mojom::MediaInProductHelpRequest request) {
+  // If we are showing the UI already, ignore the request.
+  if (media_in_product_help_)

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

sammc@, is this the correct way to ignore requests from multiple frames? And
from different elements in the same frame?

[Sam McNally, 2017/07/07 05:22:58]

Yes. There will be a race between an existing connection's closure being
detected and a new connection request arriving, but I suspect this won't be a
problem in practice.

+    return;
+
+  media_in_product_help_ = base::MakeUnique<MediaInProductHelp>(
+      render_frame_host, this, std::move(request));
+}
+
+void MediaInProductHelpManager::ShowInProductHelpWidget(
+    const gfx::Rect& rect_in_main_frame) {
+  client_->ShowMediaDownloadInProductHelp(rect_in_main_frame);
+}
+
+void MediaInProductHelpManager::OnConnectionError() {
+  DCHECK(media_in_product_help_);
+  client_->DismissMediaDownloadInProductHelp();
+}