O3D Mac: Add CoreAnimation support

plugin/mac/graphics_utils_mac.mm

 /*
  * Copyright 2009, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 64 matching lines @@
     SInt32 minor = 0;
     // These selectors don't exist pre 10.4 but as we check the error
     // the function will correctly return NO which is the right answer.
     result = ((::Gestalt(gestaltSystemVersionMajor,  &major) == noErr) &&
               (::Gestalt(gestaltSystemVersionMinor,  &minor) == noErr) &&
               ((major > 10) || (major == 10 && minor >= 5)));
     isCached = true;
   }
   return result;
 }
+  
+// Returns whether OS is 10.6 (Snow Leopard) or higher.
+bool IsMacOSTenSixOrHigher() {
+  static bool isCached = false, result = false;
+  
+  if (!isCached) {
+    SInt32 major = 0;
+    SInt32 minor = 0;
+    // These selectors don't exist pre 10.4 but as we check the error
+    // the function will correctly return NO which is the right answer.
+    result = ((::Gestalt(gestaltSystemVersionMajor,  &major) == noErr) &&
+              (::Gestalt(gestaltSystemVersionMinor,  &minor) == noErr) &&
+              ((major > 10) || (major == 10 && minor >= 6)));
+    isCached = true;
+  }
+  return result;
+}
 
-
 Rect CGRect2Rect(const CGRect &inRect) {
   Rect outRect;
   outRect.left = inRect.origin.x;
   outRect.top = inRect.origin.y;
   outRect.right = inRect.origin.x + inRect.size.width;
   outRect.bottom = inRect.origin.y + inRect.size.height;
   return outRect;
 }
 
 
@@ skipping 28 matching lines @@
   CGContextAddArcToPoint(context, lx, ty, lx, cy, radius);
   CGContextClosePath(context);
 
   if (fill)
     CGContextFillPath(context);
   else
     CGContextStrokePath(context);
 }
 
 }  // namespace o3d