Add hooks for GL_EXT_debug_markers for Skia

ui/gl/gl_bindings_skia_in_process.cc

Index: ui/gl/gl_bindings_skia_in_process.cc
diff --git a/ui/gl/gl_bindings_skia_in_process.cc b/ui/gl/gl_bindings_skia_in_process.cc
index 38e0f16f61f362a4129a7a44355052c809e92a30..2121f0c0a12bc0890cf9605f2f4afc03e3cc9ceb 100644
--- a/ui/gl/gl_bindings_skia_in_process.cc
+++ b/ui/gl/gl_bindings_skia_in_process.cc
@@ -346,6 +346,10 @@ GLint StubGLGetUniformLocation(GLuint program, const char* name) {
   return glGetUniformLocation(program, name);
 }
 
+GLvoid StubGLInsertEventMarker(GLsizei length, const char* marker) {
+    glInsertEventMarkerEXT(length, marker);

[piman, 2014/03/13 00:29:23]

nit: 2 space indent (same below).

[piman, 2014/03/13 00:29:23]

Note: this has different behavior than the command-buffer version.
For the in-process case, this would send the marker to GL.
For the command buffer case, this would be handled at the command-buffer level,
fed to about:tracing.

This is not necessarily a problem, just making sure we have the right
expectations.

+}
+
 GLvoid StubGLLineWidth(GLfloat width) {
   glLineWidth(width);
 }
@@ -362,6 +366,14 @@ GLvoid StubGLPixelStorei(GLenum pname, GLint param) {
   glPixelStorei(pname, param);
 }
 
+GLvoid StubGLPopGroupMarker() {
+    glPopGroupMarkerEXT();
+}
+
+GLvoid StubGLPushGroupMarker(GLsizei length, const char* marker) {
+    glPushGroupMarkerEXT(length, marker);
+}
+
 GLvoid StubGLQueryCounter(GLuint id, GLenum target) {
   glQueryCounter(id, target);
 }