Mac: Add partial swap support to NSOpenGLContext path

content/common/gpu/image_transport_surface.h

Index: content/common/gpu/image_transport_surface.h
diff --git a/content/common/gpu/image_transport_surface.h b/content/common/gpu/image_transport_surface.h
index c0bceaba3e90f912d1a1dcff37ef8260c2e75cb1..397dd78a99e804ce75a5ef6d0e8197797059569a 100644
--- a/content/common/gpu/image_transport_surface.h
+++ b/content/common/gpu/image_transport_surface.h
@@ -22,8 +22,10 @@
 #include "ui/gfx/swap_result.h"
 #include "ui/gl/gl_surface.h"
 
+#if defined(OS_MACOSX)
 struct AcceleratedSurfaceMsg_BufferPresented_Params;
 struct GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params;
+#endif
 
 namespace gfx {
 class GLSurface;
@@ -122,8 +124,10 @@ class ImageTransportHelper
 
   // Helper send functions. Caller fills in the surface specific params
   // like size and surface id. The helper fills in the rest.
+#if defined(OS_MACOSX)
   void SendAcceleratedSurfaceBuffersSwapped(
       GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params);
+#endif
 
   void SetPreemptByFlag(
       scoped_refptr<gpu::PreemptionFlag> preemption_flag);