cc : Compute visible rects dynamically (1)

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index dd62a982aa04f2c574c34248ee6d12cdf8c3a8f3..98b63c8d11934f7968257a8e3ed8c13eae8407a3 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -921,7 +921,9 @@ void LayerTreeImpl::SetElementIdsForTesting() {
   }
 }
 
-bool LayerTreeImpl::UpdateDrawProperties(bool update_lcd_text) {
+bool LayerTreeImpl::UpdateDrawProperties(
+    bool update_lcd_text,
+    bool force_skip_verify_visible_rect_calculations) {
   if (!needs_update_draw_properties_)
     return true;
 
@@ -949,6 +951,13 @@ bool LayerTreeImpl::UpdateDrawProperties(bool update_lcd_text) {
     bool can_render_to_separate_surface =
         (!is_in_resourceless_software_draw_mode());
 
+    // We verify visible rect calculations whenever we verify clip tree
+    // calculations except when this function is explicitly passed a flag asking
+    // us to skip it.
+    bool verify_visible_rect_calculations =
+        force_skip_verify_visible_rect_calculations
+            ? false
+            : settings().verify_clip_tree_calculations;
     LayerTreeHostCommon::CalcDrawPropsImplInputs inputs(
         layer_list_[0], DrawViewportSize(),
         layer_tree_host_impl_->DrawTransform(), device_scale_factor(),
@@ -959,6 +968,7 @@ bool LayerTreeImpl::UpdateDrawProperties(bool update_lcd_text) {
         can_render_to_separate_surface,
         settings().layer_transforms_should_scale_layer_contents,
         settings().verify_clip_tree_calculations,
+        verify_visible_rect_calculations,
         settings().verify_transform_tree_calculations,
         &render_surface_layer_list_, &property_trees_);
     LayerTreeHostCommon::CalculateDrawProperties(&inputs);