Pull gpu CmdBuf service/client shared GpuMemoryBuffer code to common

gpu/command_buffer_common.gypi

Index: gpu/command_buffer_common.gypi
diff --git a/gpu/command_buffer_common.gypi b/gpu/command_buffer_common.gypi
index 1831a92cea9d0ab56f39d995fe575f989dd48892..f822844f97ea0d361eba21fc203362f0827fabd4 100644
--- a/gpu/command_buffer_common.gypi
+++ b/gpu/command_buffer_common.gypi
@@ -5,6 +5,7 @@
 {
   'dependencies': [
     '../third_party/khronos/khronos.gyp:khronos_headers',
+    '../third_party/mesa/mesa.gyp:mesa_headers',
   ],
   'sources': [
     'command_buffer/common/bitfield_helpers.h',
@@ -38,4 +39,12 @@
     'command_buffer/common/value_state.cc',
     'command_buffer/common/value_state.h',
   ],
+  'target_conditions': [
+    ['>(nacl_untrusted_build) == 0', {
+      'sources+': [
+        'command_buffer/common/gpu_memory_buffer_support.cc',
+        'command_buffer/common/gpu_memory_buffer_support.h',
+      ],
+    }],
+  ],
 }