gpu: Associate all GpuMemoryBuffers with unique IDs.

ui/gfx/gpu_memory_buffer.h

Index: ui/gfx/gpu_memory_buffer.h
diff --git a/ui/gfx/gpu_memory_buffer.h b/ui/gfx/gpu_memory_buffer.h
index 237bf4760e33be6e1d3227c5aaf22fab6e144c7e..e6ce5d25af8da9069b5ae3b310c281ae8df1c36c 100644
--- a/ui/gfx/gpu_memory_buffer.h
+++ b/ui/gfx/gpu_memory_buffer.h
@@ -9,10 +9,6 @@
 #include "build/build_config.h"
 #include "ui/gfx/gfx_export.h"
 
-#if defined(USE_X11)
-#include "ui/gfx/x/x11_types.h"
-#endif
-
 extern "C" typedef struct _ClientBuffer* ClientBuffer;
 
 namespace gfx {
@@ -22,31 +18,21 @@ enum GpuMemoryBufferType {
   SHARED_MEMORY_BUFFER,
   IO_SURFACE_BUFFER,
   SURFACE_TEXTURE_BUFFER,
-  X11_PIXMAP_BUFFER,
   OZONE_NATIVE_BUFFER,
   GPU_MEMORY_BUFFER_TYPE_LAST = OZONE_NATIVE_BUFFER
 };
 
-struct GpuMemoryBufferId {
-  GpuMemoryBufferId() : primary_id(0), secondary_id(0) {}
-  GpuMemoryBufferId(int32 primary_id, int32 secondary_id)
-      : primary_id(primary_id), secondary_id(secondary_id) {}
-  int32 primary_id;
-  int32 secondary_id;
-};
+using GpuMemoryBufferId = int32;
 
 struct GFX_EXPORT GpuMemoryBufferHandle {
   GpuMemoryBufferHandle();
   bool is_null() const { return type == EMPTY_BUFFER; }
   GpuMemoryBufferType type;
+  GpuMemoryBufferId id;
   base::SharedMemoryHandle handle;
-  GpuMemoryBufferId global_id;
 #if defined(OS_MACOSX)
   uint32 io_surface_id;
 #endif
-#if defined(USE_X11)
-  XID pixmap;
-#endif
 };
 
 // This interface typically correspond to a type of shared memory that is also