Mirroring service: Observe the target WebContents for tab mirroring.

Observe the target WebContents for Tab/OffscreenTab mirroring.

Bug: 734672
Change-Id: I65194a345f81b38967396c80e5f614d4119782e4
Reviewed-on: https://chromium-review.googlesource.com/1176110Reviewed-by: Yuri Wiitala <miu@chromium.org>
Commit-Queue: Xiangjun Zhang <xjz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#586097}

chrome/browser/media/cast_mirroring_service_host.cc

@@ -124,6 +124,9 @@ CastMirroringServiceHost::CastMirroringServiceHost(
     content::DesktopMediaID source_media_id)
     : source_media_id_(source_media_id) {
   DCHECK(source_media_id_.type != content::DesktopMediaID::TYPE_NONE);
+  // Observe the target WebContents for Tab/OffscreenTab mirroring.
+  if (source_media_id_.type == content::DesktopMediaID::TYPE_WEB_CONTENTS)
+    Observe(GetContents(source_media_id_.web_contents_id));
 }
 
 CastMirroringServiceHost::~CastMirroringServiceHost() {
@@ -165,10 +168,7 @@ void CastMirroringServiceHost::CreateAudioStream(
     uint32_t total_segments) {
   content::WebContents* source_web_contents = nullptr;
   if (source_media_id_.type == content::DesktopMediaID::TYPE_WEB_CONTENTS) {
-    source_web_contents = content::WebContents::FromRenderFrameHost(
-        content::RenderFrameHost::FromID(
-            source_media_id_.web_contents_id.render_process_id,
-            source_media_id_.web_contents_id.main_render_frame_id));
+    source_web_contents = web_contents();
     if (!source_web_contents) {
       VLOG(1) << "Failed to create audio stream: Invalid source.";
       return;
@@ -199,8 +199,7 @@ void CastMirroringServiceHost::ConnectToRemotingSource(
     media::mojom::RemoterPtr remoter,
     media::mojom::RemotingSourceRequest request) {
   if (source_media_id_.type == content::DesktopMediaID::TYPE_WEB_CONTENTS) {
-    content::WebContents* source_contents =
-        GetContents(source_media_id_.web_contents_id);
+    content::WebContents* const source_contents = web_contents();
     if (source_contents) {
       CastRemotingConnector::Get(source_contents)
           ->ConnectWithMediaRemoter(std::move(remoter), std::move(request));
@@ -208,4 +207,9 @@ void CastMirroringServiceHost::ConnectToRemotingSource(
   }
 }
 
+void CastMirroringServiceHost::WebContentsDestroyed() {
+  // TODO(xjz): Stop the mirroring if connected to the MirroringService.
+  // Implementation will be added in a later CL.
+}
+
 }  // namespace mirroring

chrome/browser/media/cast_mirroring_service_host.h

@@ -9,6 +9,7 @@
 #include "components/mirroring/mojom/mirroring_service_host.mojom.h"
 #include "components/mirroring/mojom/resource_provider.mojom.h"
 #include "content/public/browser/desktop_media_id.h"
+#include "content/public/browser/web_contents_observer.h"
 
 namespace content {
 class AudioLoopbackStreamCreator;
@@ -22,7 +23,8 @@ namespace mirroring {
 //
 // TODO(xjz): Adds the implementation to connect to Mirroring Service.
 class CastMirroringServiceHost final : public mojom::MirroringServiceHost,
-                                       public mojom::ResourceProvider {
+                                       public mojom::ResourceProvider,
+                                       public content::WebContentsObserver {
  public:
   static void GetForTab(content::WebContents* target_contents,
                         mojom::MirroringServiceHostRequest request);
@@ -57,6 +59,9 @@ class CastMirroringServiceHost final : public mojom::MirroringServiceHost,
       media::mojom::RemoterPtr remoter,
       media::mojom::RemotingSourceRequest request) override;
 
+  // content::WebContentsObserver implementation.
+  void WebContentsDestroyed() override;
+
   // Describes the media source for this mirroring session.
   const content::DesktopMediaID source_media_id_;