Update from https://crrev.com/317530

gpu/command_buffer/build_gles2_cmd_buffer.py

Index: gpu/command_buffer/build_gles2_cmd_buffer.py
diff --git a/gpu/command_buffer/build_gles2_cmd_buffer.py b/gpu/command_buffer/build_gles2_cmd_buffer.py
index ca391507be2cbff74f63bbbbff681d3382e00f57..141d2599019041dc1417045a8ca4ee2acbde104d 100755
--- a/gpu/command_buffer/build_gles2_cmd_buffer.py
+++ b/gpu/command_buffer/build_gles2_cmd_buffer.py
@@ -1429,6 +1429,17 @@ _NAMED_TYPE_INFO = {
       '1',
     ],
   },
+  'SyncFlushFlags': {
+    'type': 'GLbitfield',
+    'is_complete': True,
+    'valid': [
+      'GL_SYNC_FLUSH_COMMANDS_BIT',
+      '0',
+    ],
+    'invalid': [
+      '0xFFFFFFFF',
+    ],
+  },
 }
 
 # This table specifies the different pepper interfaces that are supported for
@@ -1642,6 +1653,14 @@ _FUNCTION_INFO = {
       '0': '0.5f'
     },
   },
+  'ClientWaitSync': {
+    'type': 'Custom',
+    'data_transfer_methods': ['shm'],
+    'cmd_args': 'GLuint sync, GLbitfieldSyncFlushFlags flags, '
+                'GLuint timeout_0, GLuint timeout_1, GLenum* result',
+    'unsafe': True,
+    'result': ['GLenum'],
+  },
   'ColorMask': {
     'type': 'StateSet',
     'state': 'ColorMask',
@@ -2909,6 +2928,14 @@ _FUNCTION_INFO = {
                 'GLsizei stride, GLuint offset',
     'client_test': False,
   },
+  'WaitSync': {
+    'type': 'Custom',
+    'cmd_args': 'GLuint sync, GLbitfieldSyncFlushFlags flags, '
+                'GLuint timeout_0, GLuint timeout_1',
+    'impl_func': False,
+    'client_test': False,
+    'unsafe': True,
+  },
   'Scissor': {
     'type': 'StateSet',
     'state': 'Scissor',
@@ -8971,11 +8998,12 @@ class GLGenerator(object):
     # Forward declaration of a few enums used in constant argument
     # to avoid including GL header files.
     enum_defines = {
-        'GL_SYNC_GPU_COMMANDS_COMPLETE': 0x9117,
+        'GL_SYNC_GPU_COMMANDS_COMPLETE': '0x9117',
+        'GL_SYNC_FLUSH_COMMANDS_BIT': '0x00000001',
       }
     file.Write('\n')
     for enum in enum_defines:
-      file.Write("#define %s 0x%x\n" % (enum, enum_defines[enum]))
+      file.Write("#define %s %s\n" % (enum, enum_defines[enum]))
     file.Write('\n')
     for func in self.functions:
       if True: