Add the plumbing that will carry a clipboard item from a chromoting client to a host.

remoting/host/event_executor_mac.cc

Index: remoting/host/event_executor_mac.cc
diff --git a/remoting/host/event_executor_mac.cc b/remoting/host/event_executor_mac.cc
index 799b89290ae919c6dce2ef87a3efc23c881a3967..7b0b6aa6a5c137451dab431bb8824c5005514740 100644
--- a/remoting/host/event_executor_mac.cc
+++ b/remoting/host/event_executor_mac.cc
@@ -24,8 +24,8 @@ namespace {
 #include "remoting/host/usb_keycode_map.h"
 #define INVALID_KEYCODE 0xffff
 
-using protocol::MouseEvent;
 using protocol::KeyEvent;
+using protocol::MouseEvent;
 
 // A class to generate events on Mac.
 class EventExecutorMac : public EventExecutor {
@@ -33,6 +33,11 @@ class EventExecutorMac : public EventExecutor {
   EventExecutorMac(MessageLoop* message_loop, Capturer* capturer);
   virtual ~EventExecutorMac() {}
 
+  // ClipboardStub interface.
+  virtual void InjectClipboardEvent(const protocol::ClipboardEvent& event)
+      OVERRIDE;
+
+  // InputStub interface.
   virtual void InjectKeyEvent(const KeyEvent& event) OVERRIDE;
   virtual void InjectMouseEvent(const MouseEvent& event) OVERRIDE;
 
@@ -245,6 +250,11 @@ uint16_t UsbKeycodeToMacKeycode(uint32_t usb_keycode) {
   return INVALID_KEYCODE;
 }
 
+void EventExecutorMac::InjectClipboardEvent(
+    const protocol::ClipboardEvent& event) {
+  // TODO(simonmorris): Implement clipboard injection.
+}
+
 void EventExecutorMac::InjectKeyEvent(const KeyEvent& event) {
   int keycode = 0;
   if (event.has_usb_keycode() && event.usb_keycode() != INVALID_KEYCODE) {