cc: Fix up code to work with concrete cc paint types

cc/layers/painted_scrollbar_layer.cc

Index: cc/layers/painted_scrollbar_layer.cc
diff --git a/cc/layers/painted_scrollbar_layer.cc b/cc/layers/painted_scrollbar_layer.cc
index d89445b8f2e86e3d66cc32cea4a46df75fd6f3b6..7fc6e9c1ae8997e9efadb082de31efb0321491e4 100644
--- a/cc/layers/painted_scrollbar_layer.cc
+++ b/cc/layers/painted_scrollbar_layer.cc
@@ -10,6 +10,8 @@
 #include "cc/base/math_util.h"
 #include "cc/input/main_thread_scrolling_reason.h"
 #include "cc/layers/painted_scrollbar_layer_impl.h"
+#include "cc/paint/paint_canvas.h"
+#include "cc/paint/paint_flags.h"
 #include "cc/resources/ui_resource_bitmap.h"
 #include "cc/trees/draw_property_utils.h"
 #include "cc/trees/layer_tree_host.h"
@@ -263,26 +265,25 @@ UIResourceBitmap PaintedScrollbarLayer::RasterizeScrollbarPart(
 
   SkBitmap skbitmap;
   skbitmap.allocN32Pixels(content_rect.width(), content_rect.height());
-  SkCanvas skcanvas(skbitmap);
+  PaintCanvas canvas(skbitmap);
 
   float scale_x =
       content_rect.width() / static_cast<float>(layer_rect.width());
   float scale_y =
       content_rect.height() / static_cast<float>(layer_rect.height());
 
-  skcanvas.scale(SkFloatToScalar(scale_x),
-                 SkFloatToScalar(scale_y));
-  skcanvas.translate(SkFloatToScalar(-layer_rect.x()),
-                     SkFloatToScalar(-layer_rect.y()));
+  canvas.scale(SkFloatToScalar(scale_x), SkFloatToScalar(scale_y));
+  canvas.translate(SkFloatToScalar(-layer_rect.x()),
+                   SkFloatToScalar(-layer_rect.y()));
 
   SkRect layer_skrect = RectToSkRect(layer_rect);
-  SkPaint paint;
+  PaintFlags paint;
   paint.setAntiAlias(false);
   paint.setBlendMode(SkBlendMode::kClear);
-  skcanvas.drawRect(layer_skrect, paint);
-  skcanvas.clipRect(layer_skrect);
+  canvas.drawRect(layer_skrect, paint);
+  canvas.clipRect(layer_skrect);
 
-  scrollbar_->PaintPart(&skcanvas, part, layer_rect);
+  scrollbar_->PaintPart(&canvas, part, layer_rect);
   // Make sure that the pixels are no longer mutable to unavoid unnecessary
   // allocation and copying.
   skbitmap.setImmutable();