Add hooks for GL_EXT_debug_marker in gpu

src/gpu/GrInOrderDrawBuffer.cpp

Index: src/gpu/GrInOrderDrawBuffer.cpp
diff --git a/src/gpu/GrInOrderDrawBuffer.cpp b/src/gpu/GrInOrderDrawBuffer.cpp
index 669167c419bbc9680bb2dabbd344a0ef8354256d..0090d28a8cf7fd92c76b73255ee59962ae7a2f37 100644
--- a/src/gpu/GrInOrderDrawBuffer.cpp
+++ b/src/gpu/GrInOrderDrawBuffer.cpp
@@ -441,6 +441,18 @@ void GrInOrderDrawBuffer::clear(const SkIRect* rect, GrColor color,
     renderTarget->ref();
 }
 
+void GrInOrderDrawBuffer::insertEventMarker(const char* marker) {
+    // TODO: adds command to buffer
+}
+
+void GrInOrderDrawBuffer::pushGroupMarker(const char* marker) {
+    // TODO: adds command to buffer
+}
+
+void GrInOrderDrawBuffer::popGroupMarker() {
+    // TODO: adds command to buffer
+}
+
 void GrInOrderDrawBuffer::reset() {
     SkASSERT(1 == fGeoPoolStateStack.count());
     this->resetVertexSource();