HUD: Show first paint invalidation in red

cc/layers/heads_up_display_layer_impl.cc

Index: cc/layers/heads_up_display_layer_impl.cc
diff --git a/cc/layers/heads_up_display_layer_impl.cc b/cc/layers/heads_up_display_layer_impl.cc
index 51c0ed28466063145376a0bef136e345daec4af0..cd98c8e94bd81feb5e1fcba2a72e4dc51b4b7572 100644
--- a/cc/layers/heads_up_display_layer_impl.cc
+++ b/cc/layers/heads_up_display_layer_impl.cc
@@ -684,6 +684,7 @@ void HeadsUpDisplayLayerImpl::DrawDebugRects(
 
   const std::vector<DebugRect>& debug_rects = debug_rect_history->debug_rects();
   std::vector<DebugRect> new_paint_rects;
+  std::vector<DebugRect> new_first_paint_rects;
 
   for (size_t i = 0; i < debug_rects.size(); ++i) {
     SkColor stroke_color = 0;
@@ -695,6 +696,9 @@ void HeadsUpDisplayLayerImpl::DrawDebugRects(
       case PAINT_RECT_TYPE:
         new_paint_rects.push_back(debug_rects[i]);
         continue;
+      case FIRST_PAINT_RECT_TYPE:
+        new_first_paint_rects.push_back(debug_rects[i]);
+        continue;
       case PROPERTY_CHANGED_RECT_TYPE:
         stroke_color = DebugColors::PropertyChangedRectBorderColor();
         fill_color = DebugColors::PropertyChangedRectFillColor();
@@ -773,13 +777,35 @@ void HeadsUpDisplayLayerImpl::DrawDebugRects(
   if (fade_step_ > 0) {
     fade_step_--;
     for (size_t i = 0; i < paint_rects_.size(); ++i) {
-      DrawDebugRect(canvas,
-                    &paint,
-                    paint_rects_[i],
-                    DebugColors::PaintRectBorderColor(fade_step_),
-                    DebugColors::PaintRectFillColor(fade_step_),
-                    DebugColors::PaintRectBorderWidth(),
-                    "");
+      bool is_first_paint = paint_rects_[i].type == FIRST_PAINT_RECT_TYPE;
+      DrawDebugRect(
+          canvas,
+          &paint,
+          paint_rects_[i],
+          DebugColors::PaintRectBorderColor(fade_step_, is_first_paint),
+          DebugColors::PaintRectFillColor(fade_step_, is_first_paint),
+          DebugColors::PaintRectBorderWidth(),
+          "");
+    }
+  }
+
+  // TODO(kouhei)
+  if (new_first_paint_rects.size()) {
+    first_paint_rects_.swap(new_first_paint_rects);
+    fade_step_f_ = DebugColors::kFadeSteps;
+  }
+  if (fade_step_f_ > 0) {
+    fade_step_f_--;
+    for (size_t i = 0; i < first_paint_rects_.size(); ++i) {
+      bool is_first_paint = first_paint_rects_[i].type == FIRST_PAINT_RECT_TYPE;
+      DrawDebugRect(
+          canvas,
+          &paint,
+          first_paint_rects_[i],
+          DebugColors::PaintRectBorderColor(fade_step_f_, is_first_paint),
+          DebugColors::PaintRectFillColor(fade_step_f_, is_first_paint),
+          DebugColors::PaintRectBorderWidth(),
+          "");
     }
   }
 }