Implemented Browser Plugin (NOT FOR REVIEW)

content/common/browser_plugin_messages.h

 // Copyright (c) 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.
 
 // Multiply-included message header, no traditional include guard.
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/process.h"
 #include "content/common/content_export.h"
 #include "content/public/common/common_param_traits.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
+#include "ppapi/c/pp_instance.h"
 #include "ui/gfx/size.h"
 
 #define IPC_MESSAGE_START BrowserPluginMsgStart
 
 // Browser plugin messages
 
 // -----------------------------------------------------------------------------
-// These messages are from the host renderer to the browser process
+// These messages are from the embedder to the browser process
 
 // A renderer sends this to the browser process when it wants to
 // create a browser plugin.  The browser will create a guest renderer process
 // if necessary.
-IPC_MESSAGE_ROUTED4(BrowserPluginHostMsg_OpenChannel,
+IPC_MESSAGE_ROUTED4(BrowserPluginHostMsg_NavigateFromEmbedder,
                     int /* plugin instance id*/,
                     long long /* frame id */,
                     std::string /* src */,
                     gfx::Size /* size */)
 
+// Initially before we create a guest renderer, browser plugin containers
+// have a placeholder called BrowserPlugin where each BrowserPlugin has a unique
+// ID. During pepper plugin initialization, the embedder page and the plugin
+// negotiate an ID of type PP_Instance. The browser talks to the guest
+// RenderView via yet another identifier called the routing ID. The browser
+// has to keep track of how all these identifiers are associated with one
+// another.
+// For reference:
+// 1. The embedder page sees the guest renderer as a plugin and so it talks
+//    to the guest via the PP_Instance identifer.
+// 2. The guest renderer talks to the browser and vice versa via a routing ID.
+// 3. The BrowserPlugin ID uniquely identifies a browser plugin container
+//    instance within an embedder.
+//    This identifier exists prior to the existence of the routing ID and the
+//    PP_Instance identifier.
+// The purpose of this message is to tell the browser to map a PP_Instance
+// identifier to BrowserPlugin identifier.
+IPC_MESSAGE_ROUTED2(BrowserPluginHostMsg_MapInstance,
+                    int /* container_id */,
+                    PP_Instance /* instance */)
+
 // -----------------------------------------------------------------------------
 // These messages are from the browser process to the guest renderer.
 
-// Creates a channel to talk to a renderer. The guest renderer will respond
-// with BrowserPluginHostMsg_ChannelCreated.
-IPC_MESSAGE_CONTROL2(BrowserPluginMsg_CreateChannel,
-                     base::ProcessHandle /* host_renderer_process_handle */,
-                     int /* host_renderer_id */)
+IPC_MESSAGE_CONTROL2(BrowserPluginMsg_CompleteNavigation,
+                     int /* guest_routing_id */,
+                     PP_Instance /* instance */)
 
 // -----------------------------------------------------------------------------
 // These messages are from the guest renderer to the browser process
 
-// Reply to BrowserPluginMsg_CreateChannel. The handle will be NULL if the
-// channel could not be established. This could be because the IPC could not be
-// created for some weird reason, but more likely that the renderer failed to
-// initialize properly.
-IPC_MESSAGE_CONTROL1(BrowserPluginHostMsg_ChannelCreated,
-                     IPC::ChannelHandle /* handle */)
+IPC_MESSAGE_ROUTED1(BrowserPluginHostMsg_ConnectToChannel,
+                    IPC::ChannelHandle /* handle */)
 
-// Indicates the guest renderer is ready in response to a ViewMsg_New
-IPC_MESSAGE_ROUTED0(BrowserPluginHostMsg_GuestReady)
-
-// A host renderer sends this message to the browser when it wants
+// A embedder sends this message to the browser when it wants
 // to resize a guest plugin container so that the guest is relaid out
 // according to the new size.
 IPC_MESSAGE_ROUTED2(BrowserPluginHostMsg_ResizeGuest,
                     int32, /* width */
                     int32  /* height */)
 
+IPC_MESSAGE_ROUTED2(BrowserPluginHostMsg_NavigateFromGuest,
+                    PP_Instance /* instance */,
+                    std::string /* src */)
+
 // -----------------------------------------------------------------------------
-// These messages are from the browser process to the host renderer.
+// These messages are from the browser process to the embedder.
 
 // A guest instance is ready to be placed.
-IPC_MESSAGE_ROUTED3(BrowserPluginMsg_GuestReady_ACK,
-                    int /* instance id */,
-                    base::ProcessHandle /* plugin_process_handle */,
-                    IPC::ChannelHandle /* handle to channel */)
+IPC_MESSAGE_CONTROL3(BrowserPluginMsg_LoadGuest,
+                     int /* instance id */,
+                     int /* guest_process_id */,
+                     IPC::ChannelHandle /* channel_handle */)
 
-