QmlProfiler: Document which thread scene graph events come from

It's very nice to see that at a glance, rather than searching around
in the code.

Change-Id: I1d1cdf10d98578ca1fe3275fdf2dfc98f6499eed
Reviewed-by: Kai Koehne <kai.koehne@digia.com>

src/libs/qmldebug/qmlprofilereventtypes.h

@@ -91,16 +91,16 @@ enum PixmapEventType {
 };
 
 enum SceneGraphFrameType {
-    SceneGraphRendererFrame,
-    SceneGraphAdaptationLayerFrame,
-    SceneGraphContextFrame,
-    SceneGraphRenderLoopFrame,
-    SceneGraphTexturePrepare,
-    SceneGraphTextureDeletion,
-    SceneGraphPolishAndSync,
-    SceneGraphWindowsRenderShow,
-    SceneGraphWindowsAnimations,
-    SceneGraphPolishFrame,
+    SceneGraphRendererFrame,        // Render Thread
+    SceneGraphAdaptationLayerFrame, // Render Thread
+    SceneGraphContextFrame,         // Render Thread
+    SceneGraphRenderLoopFrame,      // Render Thread
+    SceneGraphTexturePrepare,       // Render Thread
+    SceneGraphTextureDeletion,      // Render Thread
+    SceneGraphPolishAndSync,        // GUI Thread
+    SceneGraphWindowsRenderShow,    // Unused
+    SceneGraphWindowsAnimations,    // GUI Thread
+    SceneGraphPolishFrame,          // GUI Thread
 
     MaximumSceneGraphFrameType
 };