Remove the SkCanvas comment API

gm/rects.cpp

Index: gm/rects.cpp
diff --git a/gm/rects.cpp b/gm/rects.cpp
index 8fb113d76f6fa19974ecc4a6e6299566950fb216..c4d5880e14b1fa5972d9c891f091c464da13fbba 100644
--- a/gm/rects.cpp
+++ b/gm/rects.cpp
@@ -252,14 +252,10 @@ protected:
     }
 
     void onDraw(SkCanvas* canvas) override {
-        SkAutoCommentBlock acb(canvas, "onDraw");
-
         canvas->translate(20 * SK_Scalar1, 20 * SK_Scalar1);
 
         int testCount = 0;
 
-        canvas->addComment("Test", "Various Paints");
-
         for (int i = 0; i < fPaints.count(); ++i) {
             for (int j = 0; j < fRects.count(); ++j, ++testCount) {
                 canvas->save();
@@ -269,8 +265,6 @@ protected:
             }
         }
 
-        canvas->addComment("Test", "Matrices");
-
         SkPaint paint;
         paint.setColor(SK_ColorWHITE);
         paint.setAntiAlias(true);