Add a content API to create a message channel.

content/browser/android/content_view_core_impl.cc

 // Copyright 2012 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/browser/android/content_view_core_impl.h"
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_array.h"
 #include "base/android/jni_string.h"
 #include "base/android/scoped_java_ref.h"
 #include "base/command_line.h"
 #include "base/json/json_writer.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "cc/layers/layer.h"
 #include "cc/layers/solid_color_layer.h"
 #include "cc/output/begin_frame_args.h"
 #include "content/browser/android/gesture_event_type.h"
 #include "content/browser/android/interstitial_page_delegate_android.h"
 #include "content/browser/android/java/gin_java_bridge_dispatcher_host.h"
 #include "content/browser/android/load_url_params.h"
 #include "content/browser/frame_host/interstitial_page_impl.h"
 #include "content/browser/frame_host/navigation_controller_impl.h"
 #include "content/browser/frame_host/navigation_entry_impl.h"
 #include "content/browser/geolocation/geolocation_dispatcher_host.h"
 #include "content/browser/media/media_web_contents_observer.h"
+#include "content/browser/message_port_service.h"
 #include "content/browser/renderer_host/compositor_impl_android.h"
 #include "content/browser/renderer_host/input/motion_event_android.h"
 #include "content/browser/renderer_host/input/web_input_event_builders_android.h"
 #include "content/browser/renderer_host/input/web_input_event_util.h"
 #include "content/browser/renderer_host/render_view_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_impl.h"
 #include "content/browser/renderer_host/render_widget_host_view_android.h"
 #include "content/browser/screen_orientation/screen_orientation_dispatcher_host.h"
 #include "content/browser/ssl/ssl_host_state.h"
 #include "content/browser/transition_request_manager.h"
@@ skipping 112 matching lines @@
       return -1;
   };
 }
 
 float GetPrimaryDisplayDeviceScaleFactor() {
   const gfx::Display& display =
       gfx::Screen::GetNativeScreen()->GetPrimaryDisplay();
   return display.device_scale_factor();
 }
 
+void CreateMessageChannelOnIOThread(
+    MessagePortMessageFilter* filter,
+    int routing_id,
+    int* port1, int* port2) {
+
+  *port1 = 0;
+  *port2 = 0;
+  MessagePortService* msp = MessagePortService::GetInstance();
+  msp->Create(routing_id, filter, port1);
+  msp->Create(routing_id, filter, port2);
+  msp->QueueMessages(*port1);
+  msp->QueueMessages(*port2);
+}
+
+void OnMessageChannelCreated(
+    ScopedJavaGlobalRef<jobject>* callback,
+    int* port1, int* port2) {
+  JNIEnv* env = AttachCurrentThread();
+  Java_ContentViewCore_onMessageChannelCreated(env, *port1, *port2,
+      callback->obj());
+}
+
 }  // namespace
 
 // Enables a callback when the underlying WebContents is destroyed, to enable
 // nulling the back-pointer.
 class ContentViewCoreImpl::ContentViewUserData
     : public base::SupportsUserData::Data {
  public:
   explicit ContentViewUserData(ContentViewCoreImpl* content_view_core)
       : content_view_core_(content_view_core) {
   }
@@ skipping 1245 matching lines @@
   ScopedJavaGlobalRef<jobject> j_callback;
   j_callback.Reset(env, callback);
   content::RenderFrameHost::JavaScriptResultCallback c_callback =
       base::Bind(&JavaScriptResultCallback, j_callback);
 
   web_contents_->GetMainFrame()->ExecuteJavaScript(
       ConvertJavaStringToUTF16(env, script),
       c_callback);
 }
 
+void ContentViewCoreImpl::CreateMessageChannel(JNIEnv* env, jobject obj,
+    jobject callback) {
+
+  ScopedJavaGlobalRef<jobject>* j_callback = new ScopedJavaGlobalRef<jobject>();
+  j_callback->Reset(env, callback);
+  RenderProcessHostImpl* rph =
+      static_cast<RenderProcessHostImpl*>(
+          web_contents_->GetRenderProcessHost());
+  MessagePortMessageFilter* mf = rph->message_port_message_filter();
+
+  int port1;

[Yaron, 2014/07/18 21:54:00]

These are stack allocated and are passing to another thread and back and the
callback will execute after this frame. I think instead you can new them and use
base::Owned on the reply to give the callback ownership.

[sgurun-gerrit only, 2014/10/28 00:41:10]

Done.

+  int port2;
+  // Create message channel on IO thread
+  BrowserThread::PostTaskAndReply(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&CreateMessageChannelOnIOThread,
+                 mf,
+                 GetWebContents()->GetRoutingID(),
+                 &port1, &port2),
+      base::Bind(&OnMessageChannelCreated,
+                 base::Owned(j_callback),
+                 &port1, &port2));
+}
+
 bool ContentViewCoreImpl::GetUseDesktopUserAgent(
     JNIEnv* env, jobject obj) {
   NavigationEntry* entry = web_contents_->GetController().GetVisibleEntry();
   return entry && entry->GetIsOverridingUserAgent();
 }
 
 void ContentViewCoreImpl::UpdateImeAdapter(long native_ime_adapter,
                                            int text_input_type,
                                            const std::string& text,
                                            int selection_start,
@@ skipping 221 matching lines @@
       reinterpret_cast<ui::WindowAndroid*>(window_android),
       retained_objects_set);
   return reinterpret_cast<intptr_t>(view);
 }
 
 bool RegisterContentViewCore(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 }  // namespace content