Implement GL_EXT_debug_marker

gpu/command_buffer/cmd_buffer_functions.txt

Index: gpu/command_buffer/cmd_buffer_functions.txt
diff --git a/gpu/command_buffer/cmd_buffer_functions.txt b/gpu/command_buffer/cmd_buffer_functions.txt
index a46a41560cbc76ea9bea71fa810231d3e15778c2..ca64fdc6eb7b5da492c6212585ecfe19e27b1fe5 100644
--- a/gpu/command_buffer/cmd_buffer_functions.txt
+++ b/gpu/command_buffer/cmd_buffer_functions.txt
@@ -157,6 +157,10 @@ GL_APICALL void         GL_APIENTRY glBeginQueryEXT (GLenumQueryTarget target, G
 GL_APICALL void         GL_APIENTRY glEndQueryEXT (GLenumQueryTarget target);
 GL_APICALL void         GL_APIENTRY glGetQueryivEXT (GLenumQueryTarget target, GLenumQueryParameter pname, GLint* params);
 GL_APICALL void         GL_APIENTRY glGetQueryObjectuivEXT (GLidQuery id, GLenumQueryObjectParameter pname, GLuint* params);
+GL_APICALL void         GL_APIENTRY glInsertEventMarkerEXT (GLsizei length, const GLchar* marker);
+GL_APICALL void         GL_APIENTRY glPushGroupMarkerEXT (GLsizei length, const GLchar* marker);
+GL_APICALL void         GL_APIENTRY glPopGroupMarkerEXT (void);
+
 // Non-GL commands.
 GL_APICALL void         GL_APIENTRY glSwapBuffers (void);
 GL_APICALL GLuint       GL_APIENTRY glGetMaxValueInBufferCHROMIUM (GLidBuffer buffer_id, GLsizei count, GLenumGetMaxIndexType type, GLuint offset);