Porting Mac keypress detection from GIPS repository.

Mac keypress detection was added specifically for GTalk.
Review URL: http://webrtc-codereview.appspot.com/124001

git-svn-id: http://webrtc.googlecode.com/svn/trunk@453 4adac7df-926f-26a2-2b94-8c16560cd09d

src/system_wrappers/source/event.cc

@@ -1,4 +1,4 @@
-/*
+c/*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
@@ -13,6 +13,10 @@
 #if defined(_WIN32)
     #include <windows.h>
     #include "event_windows.h"
+#elif defined(WEBRTC_MAC_INTEL)
+    #include <ApplicationServices/ApplicationServices.h>
+    #include <pthread.h>
+    #include "event_posix.h"
 #else
     #include <pthread.h>
     #include "event_posix.h"
@@ -45,6 +49,21 @@ int EventWrapper::KeyPressed()
     {
         return 0;
     }
+#elif defined(WEBRTC_MAC_INTEL)
+    bool keyDown = false;
+    // loop through all Mac virtual key constant values
+    for(int keyIndex = 0; keyIndex <= 0x5C; keyIndex++) 
+    {
+        keyDown |= CGEventSourceKeyState(kCGEventSourceStateHIDSystemState, keyIndex);
+    }
+    if(keyDown)
+    {
+        return 1;
+    }
+    else
+    {
+        return 0;
+    } 
 #else
     return -1;
 #endif

src/system_wrappers/source/system_wrappers.gyp

@@ -97,6 +97,11 @@
           'sources': [
             'cpu_mac.cc',
           ],
+          'link_settings': {
+            'libraries': [
+              '$(SDKROOT)/System/Library/Frameworks/ApplicationServices.framework',
+            ],
+          },
         }],
         ['OS=="win"', {
           'sources': [