cc: Remove OverdrawMetrics and --trace-overdraw flag.

cc/layers/scrollbar_layer_unittest.cc

Index: cc/layers/scrollbar_layer_unittest.cc
diff --git a/cc/layers/scrollbar_layer_unittest.cc b/cc/layers/scrollbar_layer_unittest.cc
index 2b2b010e68b7eb8f15e020856ae39e6f73d196e8..ccba3ae172c53a5f04f377c226acf83b81e4047f 100644
--- a/cc/layers/scrollbar_layer_unittest.cc
+++ b/cc/layers/scrollbar_layer_unittest.cc
@@ -652,7 +652,8 @@ class ScrollbarLayerTestResourceCreation : public testing::Test {
     EXPECT_EQ(scrollbar_layer->layer_tree_host(), layer_tree_host_.get());
 
     ResourceUpdateQueue queue;
-    OcclusionTracker<Layer> occlusion_tracker(gfx::Rect(), false);
+    gfx::Rect screen_space_clip_rect;
+    OcclusionTracker<Layer> occlusion_tracker(screen_space_clip_rect);
 
     scrollbar_layer->SavePaintProperties();
     for (int update_counter = 0; update_counter < num_updates; update_counter++)
@@ -738,7 +739,8 @@ class ScaledScrollbarLayerTestResourceCreation : public testing::Test {
     EXPECT_EQ(scrollbar_layer->layer_tree_host(), layer_tree_host_.get());
 
     ResourceUpdateQueue queue;
-    OcclusionTracker<Layer> occlusion_tracker(gfx::Rect(), false);
+    gfx::Rect screen_space_clip_rect;
+    OcclusionTracker<Layer> occlusion_tracker(screen_space_clip_rect);
     scrollbar_layer->SavePaintProperties();
     scrollbar_layer->Update(&queue, &occlusion_tracker);
 
@@ -814,7 +816,8 @@ class ScaledScrollbarLayerTestScaledRasterization : public testing::Test {
                   scaled_size.height());
 
     ResourceUpdateQueue queue;
-    OcclusionTracker<Layer> occlusion_tracker(gfx::Rect(), false);
+    gfx::Rect screen_space_clip_rect;
+    OcclusionTracker<Layer> occlusion_tracker(screen_space_clip_rect);
     scrollbar_layer->SavePaintProperties();
 
     scrollbar_layer->Update(&queue, &occlusion_tracker);