cc: Move occlusion debug rects into the debug layer borders.

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index f74228bdacf694cca1ac36e0c2503da2ba4fc510..fd84e5814174b89720237f2f0915e5bedd5015cd 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -327,6 +327,22 @@ void LayerImpl::AppendDebugBorderQuad(RenderPass* render_pass,
       render_pass->CreateAndAppendDrawQuad<DebugBorderDrawQuad>();
   debug_border_quad->SetNew(
       shared_quad_state, quad_rect, visible_quad_rect, color, width);
+  if (contents_opaque()) {
+    // When opaque, draw a second inner border that is thicker than the outer
+    // border, but more transparent.
+    static const float kFillOpacity = 0.3f;
+    SkColor fill_color = SkColorSetA(
+        color, static_cast<uint8_t>(SkColorGetA(color) * kFillOpacity));
+    float fill_width = width * 3;
+    gfx::Rect fill_rect = quad_rect;
+    fill_rect.Inset(fill_width / 2.f, fill_width / 2.f);
+    gfx::Rect visible_fill_rect =
+        gfx::IntersectRects(visible_quad_rect, fill_rect);
+    DebugBorderDrawQuad* fill_quad =
+        render_pass->CreateAndAppendDrawQuad<DebugBorderDrawQuad>();
+    fill_quad->SetNew(shared_quad_state, fill_rect, visible_fill_rect,
+                      fill_color, fill_width);
+  }
 }
 
 bool LayerImpl::HasDelegatedContent() const {