Add APIs to the client plugin to re-map and trap key events.

remoting/client/plugin/chromoting_instance.h

Index: remoting/client/plugin/chromoting_instance.h
diff --git a/remoting/client/plugin/chromoting_instance.h b/remoting/client/plugin/chromoting_instance.h
index 5e36fc8d026e4267d49d562fe5fca336290980ef..7a580399f27523b363b08362f9324c359bd5d561 100644
--- a/remoting/client/plugin/chromoting_instance.h
+++ b/remoting/client/plugin/chromoting_instance.h
@@ -27,6 +27,7 @@
 #include "ppapi/cpp/private/instance_private.h"
 #include "remoting/base/scoped_thread_proxy.h"
 #include "remoting/client/client_context.h"
+#include "remoting/client/key_event_mapper.h"
 #include "remoting/client/plugin/pepper_plugin_thread_delegate.h"
 #include "remoting/proto/event.pb.h"
 #include "remoting/protocol/clipboard_stub.h"
@@ -141,6 +142,8 @@ class ChromotingInstance :
   void OnIncomingIq(const std::string& iq);
   void ReleaseAllKeys();
   void InjectKeyEvent(const protocol::KeyEvent& event);
+  void RemapKey(uint32 in_usb_keycode, uint32 out_usb_keycode);
+  void TrapKey(uint32 usb_keycode, bool trap);
   void SendClipboardItem(const std::string& mime_type, const std::string& item);
 
   // Return statistics record by ChromotingClient.
@@ -176,6 +179,9 @@ class ChromotingInstance :
   void PostChromotingMessage(const std::string& method,
                              scoped_ptr<base::DictionaryValue> data);
 
+  // Posts trapped keys to the web-app to handle.
+  void SendTrappedKey(uint32 usb_keycode, bool pressed);
+
   // Callback for PepperXmppProxy.
   void SendOutgoingIq(const std::string& iq);
 
@@ -194,6 +200,7 @@ class ChromotingInstance :
   scoped_refptr<RectangleUpdateDecoder> rectangle_decoder_;
   scoped_ptr<MouseInputFilter> mouse_input_filter_;
   scoped_ptr<protocol::InputEventTracker> input_tracker_;
+  KeyEventMapper key_mapper_;
   scoped_ptr<PepperInputHandler> input_handler_;
   scoped_ptr<ChromotingClient> client_;