Efficiently handle image layer scaling

cc/debug_colors.cc

Index: cc/debug_colors.cc
diff --git a/cc/debug_colors.cc b/cc/debug_colors.cc
index 5a98b909eae325b673aaa846b017d6df2c4585c7..e41435d759ac168b8e4610417f959cb1d543b0d1 100644
--- a/cc/debug_colors.cc
+++ b/cc/debug_colors.cc
@@ -18,6 +18,10 @@ static const float Scale(float width, const LayerTreeImpl* tree_impl) {
 SkColor DebugColors::TiledContentLayerBorderColor() { return SkColorSetARGB(128, 255, 128, 0); }
 int DebugColors::TiledContentLayerBorderWidth(const LayerTreeImpl* tree_impl) { return Scale(2, tree_impl); }
 
+// Image layers are olive.
+SkColor DebugColors::ImageLayerBorderColor() { return SkColorSetARGB(128, 128, 128, 0); }
+int DebugColors::ImageLayerBorderWidth(const LayerTreeImpl* tree_impl) { return Scale(2, tree_impl); }
+
 // Non-tiled content layers area green.
 SkColor DebugColors::ContentLayerBorderColor() { return SkColorSetARGB(128, 0, 128, 32); }
 int DebugColors::ContentLayerBorderWidth(const LayerTreeImpl* tree_impl) { return Scale(2, tree_impl); }