Revert of cc: Make PaintedScrollbarLayer not use ContentsScalingLayer

cc/layers/painted_scrollbar_layer_impl_unittest.cc

Index: cc/layers/painted_scrollbar_layer_impl_unittest.cc
diff --git a/cc/layers/painted_scrollbar_layer_impl_unittest.cc b/cc/layers/painted_scrollbar_layer_impl_unittest.cc
index 36cfe756484215c23218ba8a58391627b43ae169..3994cc36ca19b323b54e004576e31ce6ddc66b94 100644
--- a/cc/layers/painted_scrollbar_layer_impl_unittest.cc
+++ b/cc/layers/painted_scrollbar_layer_impl_unittest.cc
@@ -4,7 +4,6 @@
 
 #include "cc/layers/painted_scrollbar_layer_impl.h"
 
-#include "cc/quads/draw_quad.h"
 #include "cc/test/layer_test_common.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ -13,8 +12,6 @@
 
 TEST(PaintedScrollbarLayerImplTest, Occlusion) {
   gfx::Size layer_size(10, 1000);
-  float scale = 2.f;
-  gfx::Size scaled_layer_size(20, 2000);
   gfx::Size viewport_size(1000, 1000);
 
   LayerTestCommon::LayerImplTest impl;
@@ -39,8 +36,6 @@
       impl.AddChildToRoot<PaintedScrollbarLayerImpl>(orientation);
   scrollbar_layer_impl->SetBounds(layer_size);
   scrollbar_layer_impl->SetContentBounds(layer_size);
-  scrollbar_layer_impl->set_internal_contents_scale_and_bounds(
-      scale, scaled_layer_size);
   scrollbar_layer_impl->SetDrawsContent(true);
   scrollbar_layer_impl->SetThumbThickness(layer_size.width());
   scrollbar_layer_impl->SetThumbLength(500);
@@ -67,17 +62,6 @@
         impl.quad_list(), occluded, &partially_occluded_count);
     EXPECT_EQ(2u, impl.quad_list().size());
     EXPECT_EQ(0u, partially_occluded_count);
-
-    // Note: this is also testing that the thumb and track are both
-    // scaled by the internal contents scale.  It's not occlusion-related
-    // but is easy to verify here.
-    const DrawQuad* thumb_quad = impl.quad_list().ElementAt(0);
-    const DrawQuad* track_quad = impl.quad_list().ElementAt(1);
-
-    gfx::Rect scaled_thumb_rect = gfx::ScaleToEnclosingRect(thumb_rect, scale);
-    EXPECT_EQ(track_quad->rect.ToString(),
-              gfx::Rect(scaled_layer_size).ToString());
-    EXPECT_EQ(thumb_quad->rect.ToString(), scaled_thumb_rect.ToString());
   }
 
   {