Browser Plugin: Implement CanGoBack/CanGoForward

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"
@@ skipping 142 matching lines @@
                      std::string /* type */)
 
 // When the guest redirects a navigation, the browser process informs the
 // embedder through the BrowserPluginMsg_LoadRedirect message.
 IPC_MESSAGE_CONTROL4(BrowserPluginMsg_LoadRedirect,
                      int /* instance_id */,
                      GURL /* old_url */,
                      GURL /* new_url */,
                      bool /* is_top_level */)
 
+IPC_STRUCT_BEGIN(BrowserPluginMsg_DidNavigate_Params)
+  // The current URL of the guest.
+  IPC_STRUCT_MEMBER(GURL, url)
+  // Indicates whether the navigation was on the top-level frame.
+  IPC_STRUCT_MEMBER(bool, is_top_level)
+  // Chrome's process ID for the guest.
+  IPC_STRUCT_MEMBER(int, process_id)
+  // The index of the current navigation entry after this navigation was
+  // committed.
+  IPC_STRUCT_MEMBER(int, current_entry_index)
+  // The number of navigation entries after this navigation was committed.
+  IPC_STRUCT_MEMBER(int, entry_count)
+IPC_STRUCT_END()
+
 // When the guest navigates, the browser process informs the embedder through
-// the BrowserPluginMsg_DidNavigate message.
-IPC_MESSAGE_CONTROL3(BrowserPluginMsg_DidNavigate,
+// the BrowserPluginMsg_DidNavigate message along with information about the
+// guest's current navigation state.
+IPC_MESSAGE_CONTROL2(BrowserPluginMsg_DidNavigate,
                      int /* instance_id */,
-                     GURL /* url */,
-                     int /* process_id */)
+                     BrowserPluginMsg_DidNavigate_Params)
 
 // When the guest crashes, the browser process informs the embedder through this
 // message.
 IPC_MESSAGE_CONTROL1(BrowserPluginMsg_GuestCrashed,
                      int /* instance_id */)
 
 IPC_STRUCT_BEGIN(BrowserPluginMsg_UpdateRect_Params)
   // The position and size of the bitmap.
   IPC_STRUCT_MEMBER(gfx::Rect, bitmap_rect)
 
@@ skipping 39 matching lines @@
 IPC_MESSAGE_CONTROL2(BrowserPluginMsg_ShouldAcceptTouchEvents,
                      int /* instance_id */,
                      bool /* accept */)
 
 // The guest has damage it wants to convey to the embedder so that it can
 // update its backing store.
 IPC_MESSAGE_CONTROL3(BrowserPluginMsg_UpdateRect,
                      int /* instance_id */,
                      int /* message_id */,
                      BrowserPluginMsg_UpdateRect_Params)