[Presentation API] Plumbing of |onstatechange| from the Mojo service to the public/platform

Removed PresentationSessionDispatcher since the session messages are going through the
PresentationService (to reduce the number of Mojo pipes used).

Depends on the Blink change: https://codereview.chromium.org/1020303004

BUG=459006

Review URL: https://codereview.chromium.org/1024903003

Cr-Commit-Position: refs/heads/master@{#322162}

content/browser/presentation/presentation_service_impl.cc

@@ -280,6 +280,11 @@ void PresentationServiceImpl::CloseSession(
   NOTIMPLEMENTED();
 }
 
+void PresentationServiceImpl::ListenForSessionStateChange(
+    const SessionStateCallback& callback) {
+  NOTIMPLEMENTED();
+}
+
 void PresentationServiceImpl::DidNavigateAnyFrame(
     content::RenderFrameHost* render_frame_host,
     const content::LoadCommittedDetails& details,

content/browser/presentation/presentation_service_impl.h

@@ -61,6 +61,9 @@ class CONTENT_EXPORT PresentationServiceImpl
           presentation::PresentationErrorPtr)>;
   using DefaultSessionMojoCallback =
       mojo::Callback<void(presentation::PresentationSessionInfoPtr)>;
+  using SessionStateCallback =
+      mojo::Callback<void(presentation::PresentationSessionInfoPtr,
+          presentation::PresentationSessionState)>;
 
   // A helper data class used by PresentationServiceImpl to do bookkeeping
   // of currently registered screen availability listeners.
@@ -166,6 +169,8 @@ class CONTENT_EXPORT PresentationServiceImpl
   void CloseSession(
       const mojo::String& presentation_url,
       const mojo::String& presentation_id) override;
+  void ListenForSessionStateChange(
+      const SessionStateCallback& callback) override;
 
   // mojo::InterfaceImpl override.
   // Note that this is called when the RenderFrameHost is deleted.

content/common/presentation/presentation_service.mojom

@@ -9,6 +9,11 @@ struct PresentationSessionInfo {
     string id;
 };
 
+enum PresentationSessionState {
+    CONNECTED,
+    DISCONNECTED
+};
+
 enum PresentationErrorType {
     NO_AVAILABLE_SCREENS,
     SESSION_REQUEST_CANCELLED,
@@ -72,4 +77,11 @@ interface PresentationService {
 
     // Called when closeSession() is called by the frame.
     CloseSession(string presentation_url, string presentation_id);
+
+    // Called when the frame is ready to process the next state change. Returns
+    // the last session state if it’s changed since the last time the callback
+    // was called. Might cause the event fired with the initial state change.
+    ListenForSessionStateChange()
+        => (PresentationSessionInfo sessionInfo,
+            PresentationSessionState newState);
 };

content/content_renderer.gypi

@@ -320,8 +320,6 @@
       'renderer/presentation/presentation_dispatcher.h',
       'renderer/presentation/presentation_session_client.cc',
       'renderer/presentation/presentation_session_client.h',
-      'renderer/presentation/presentation_session_dispatcher.cc',
-      'renderer/presentation/presentation_session_dispatcher.h',
       'renderer/push_messaging/push_messaging_dispatcher.cc',
       'renderer/push_messaging/push_messaging_dispatcher.h',
       'renderer/render_font_warmup_win.cc',

content/renderer/presentation/presentation_dispatcher.cc

@@ -33,6 +33,19 @@ blink::WebPresentationError::ErrorType GetWebPresentationErrorTypeFromMojo(
   }
 }
 
+blink::WebPresentationSessionState GetWebPresentationSessionStateFromMojo(
+        presentation::PresentationSessionState mojoSessionState) {
+  switch (mojoSessionState) {
+    case presentation::PRESENTATION_SESSION_STATE_CONNECTED:
+      return blink::WebPresentationSessionState::Connected;
+    case presentation::PRESENTATION_SESSION_STATE_DISCONNECTED:
+      return blink::WebPresentationSessionState::Disconnected;
+  }
+
+  NOTREACHED();
+  return blink::WebPresentationSessionState::Disconnected;
+}
+
 GURL GetPresentationURLFromFrame(content::RenderFrame* frame) {
   DCHECK(frame);
 
@@ -161,11 +174,8 @@ void PresentationDispatcher::OnDefaultSessionStarted(
       base::Unretained(this)));
 
   DCHECK(!session_info.is_null());
-  PresentationSessionDispatcher* session_dispatcher =
-      new PresentationSessionDispatcher(session_info.Pass());
-  presentation_session_dispatchers_.push_back(session_dispatcher);
   controller_->didStartDefaultSession(
-      new PresentationSessionClient(session_dispatcher));
+      new PresentationSessionClient(session_info.Pass()));
 }
 
 void PresentationDispatcher::OnSessionCreated(
@@ -182,10 +192,23 @@ void PresentationDispatcher::OnSessionCreated(
   }
 
   DCHECK(!session_info.is_null());
-  PresentationSessionDispatcher* session_dispatcher =
-      new PresentationSessionDispatcher(session_info.Pass());
-  presentation_session_dispatchers_.push_back(session_dispatcher);
-  callback->onSuccess(new PresentationSessionClient(session_dispatcher));
+  callback->onSuccess(new PresentationSessionClient(session_info.Pass()));
+}
+
+void PresentationDispatcher::OnSessionStateChange(
+    presentation::PresentationSessionInfoPtr session_info,
+    presentation::PresentationSessionState session_state) {
+  if (!controller_)
+    return;
+
+  presentation_service_->ListenForSessionStateChange(base::Bind(
+      &PresentationDispatcher::OnSessionStateChange,
+      base::Unretained(this)));
+
+  DCHECK(!session_info.is_null());
+  controller_->didChangeSessionState(
+      new PresentationSessionClient(session_info.Pass()),
+      GetWebPresentationSessionStateFromMojo(session_state));
 }
 
 void PresentationDispatcher::ConnectToPresentationServiceIfNeeded() {
@@ -197,6 +220,9 @@ void PresentationDispatcher::ConnectToPresentationServiceIfNeeded() {
   presentation_service_->ListenForDefaultSessionStart(base::Bind(
       &PresentationDispatcher::OnDefaultSessionStarted,
       base::Unretained(this)));
+  presentation_service_->ListenForSessionStateChange(base::Bind(
+      &PresentationDispatcher::OnSessionStateChange,
+      base::Unretained(this)));
 }
 
 }  // namespace content

content/renderer/presentation/presentation_dispatcher.h

@@ -6,11 +6,9 @@
 #define CONTENT_RENDERER_PRESENTATION_PRESENTATION_DISPATCHER_H_
 
 #include "base/compiler_specific.h"
-#include "base/memory/scoped_vector.h"
 #include "content/common/content_export.h"
 #include "content/common/presentation/presentation_service.mojom.h"
 #include "content/public/renderer/render_frame_observer.h"
-#include "content/renderer/presentation/presentation_session_dispatcher.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationClient.h"
 
 namespace blink {
@@ -57,6 +55,9 @@ class CONTENT_EXPORT PresentationDispatcher
       presentation::PresentationErrorPtr error);
   void OnDefaultSessionStarted(
       presentation::PresentationSessionInfoPtr session_info);
+  void OnSessionStateChange(
+      presentation::PresentationSessionInfoPtr session_info,
+      presentation::PresentationSessionState session_state);
 
   void ConnectToPresentationServiceIfNeeded();
 
@@ -67,14 +68,6 @@ class CONTENT_EXPORT PresentationDispatcher
   // Used as a weak reference. Can be null since lifetime is bound to the frame.
   blink::WebPresentationController* controller_;
   presentation::PresentationServicePtr presentation_service_;
-
-  // Wrappers around the PresentationSessionPtr corresponding to each Javascript
-  // PresentationSession object passed back to the frame.
-  // TODO(avayvod): Switch to base::IDMap when the lookup by presentation id is
-  // needed.
-  using PresentationSessionDispatchers =
-      ScopedVector<PresentationSessionDispatcher>;
-  PresentationSessionDispatchers presentation_session_dispatchers_;
 };
 
 }  // namespace content

content/renderer/presentation/presentation_session_client.cc

@@ -5,15 +5,14 @@
 #include "content/renderer/presentation/presentation_session_client.h"
 
 #include "base/logging.h"
-#include "content/renderer/presentation/presentation_session_dispatcher.h"
 #include "third_party/WebKit/public/platform/WebString.h"
 
 namespace content {
 
 PresentationSessionClient::PresentationSessionClient(
-    PresentationSessionDispatcher* dispatcher)
-    : url_(blink::WebString::fromUTF8(dispatcher->GetUrl())),
-      id_(blink::WebString::fromUTF8(dispatcher->GetId())) {
+    presentation::PresentationSessionInfoPtr session_info)
+    : url_(blink::WebString::fromUTF8(session_info->url)),
+      id_(blink::WebString::fromUTF8(session_info->id)) {
 }
 
 PresentationSessionClient::~PresentationSessionClient() {

content/renderer/presentation/presentation_session_client.h

@@ -7,18 +7,18 @@
 
 #include "base/compiler_specific.h"
 #include "content/common/content_export.h"
+#include "content/common/presentation/presentation_service.mojom.h"
 #include "third_party/WebKit/public/platform/modules/presentation/WebPresentationSessionClient.h"
 
 namespace content {
 
-class PresentationSessionDispatcher;
-
 // PresentationSessionClient is passed to the Blink layer if presentation
 // session has been created successfully. Owned by the callback.
 class CONTENT_EXPORT PresentationSessionClient
     : public NON_EXPORTED_BASE(blink::WebPresentationSessionClient) {
  public:
-  explicit PresentationSessionClient(PresentationSessionDispatcher* dispatcher);
+  explicit PresentationSessionClient(
+        presentation::PresentationSessionInfoPtr session_info);
   ~PresentationSessionClient() override;
 
   // WebPresentationSessionClient implementation.

content/renderer/presentation/presentation_session_dispatcher.cc

-// Copyright 2015 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 "content/renderer/presentation/presentation_session_dispatcher.h"
-
-#include "base/logging.h"
-
-namespace content {
-
-PresentationSessionDispatcher::PresentationSessionDispatcher(
-    presentation::PresentationSessionInfoPtr session_info)
-    : session_info_(session_info.Pass()) {
-}
-
-PresentationSessionDispatcher::~PresentationSessionDispatcher() {
-}
-
-const mojo::String& PresentationSessionDispatcher::GetUrl() const {
-  DCHECK(!session_info_.is_null());
-  return session_info_->url;
-}
-
-const mojo::String& PresentationSessionDispatcher::GetId() const {
-  DCHECK(!session_info_.is_null());
-  return session_info_->id;
-}
-
-}  // namespace content

content/renderer/presentation/presentation_session_dispatcher.h

-// Copyright 2015 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_PRESENTATION_PRESENTATION_SESSION_DISPATCHER_H_
-#define CONTENT_RENDERER_PRESENTATION_PRESENTATION_SESSION_DISPATCHER_H_
-
-#include "base/compiler_specific.h"
-#include "content/common/content_export.h"
-#include "content/common/presentation/presentation_service.mojom.h"
-
-namespace content {
-
-// A wrapper around the Mojo PresentationSession remote object.
-class CONTENT_EXPORT PresentationSessionDispatcher {
- public:
-  explicit PresentationSessionDispatcher(
-      presentation::PresentationSessionInfoPtr session_info);
-  ~PresentationSessionDispatcher();
-
-  const mojo::String& GetUrl() const;
-  const mojo::String& GetId() const;
-
- private:
-  presentation::PresentationSessionInfoPtr session_info_;
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_PRESENTATION_PRESENTATION_SESSION_DISPATCHER_H_