Make IsSolidColor() a property on CC scrollbar layers.

cc/layers/scrollbar_layer_impl.cc

Index: cc/layers/scrollbar_layer_impl.cc
diff --git a/cc/layers/scrollbar_layer_impl.cc b/cc/layers/scrollbar_layer_impl.cc
index b8da4b65cfd362c441fae3b0ddc35dd306d2f4e9..029da1183f6fb146ef25f4638f1da17b8d503614 100644
--- a/cc/layers/scrollbar_layer_impl.cc
+++ b/cc/layers/scrollbar_layer_impl.cc
@@ -18,16 +18,19 @@ namespace cc {
 scoped_ptr<ScrollbarLayerImpl> ScrollbarLayerImpl::Create(
     LayerTreeImpl* tree_impl,
     int id,
-    ScrollbarOrientation orientation) {
+    ScrollbarOrientation orientation,
+    bool is_solid_color) {
   return make_scoped_ptr(new ScrollbarLayerImpl(tree_impl,
                                                 id,
-                                                orientation));
+                                                orientation,
+                                                is_solid_color));
 }
 
 ScrollbarLayerImpl::ScrollbarLayerImpl(
     LayerTreeImpl* tree_impl,
     int id,
-    ScrollbarOrientation orientation)
+    ScrollbarOrientation orientation,
+    bool is_solid_color)
     : LayerImpl(tree_impl, id),
       track_resource_id_(0),
       thumb_resource_id_(0),
@@ -45,7 +48,9 @@ ScrollbarLayerImpl::ScrollbarLayerImpl(
       is_scroll_view_scrollbar_(false),
       enabled_(false),
       is_custom_scrollbar_(false),
-      is_overlay_scrollbar_(false) {}
+      is_overlay_scrollbar_(false),
+      is_solid_color_(is_solid_color) {
+}
 
 ScrollbarLayerImpl::~ScrollbarLayerImpl() {}
 
@@ -55,9 +60,8 @@ ScrollbarLayerImpl* ScrollbarLayerImpl::ToScrollbarLayer() {
 
 scoped_ptr<LayerImpl> ScrollbarLayerImpl::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
-  return ScrollbarLayerImpl::Create(tree_impl,
-                                    id(),
-                                    orientation_).PassAs<LayerImpl>();
+  return ScrollbarLayerImpl::Create(
+      tree_impl, id(), orientation_, is_solid_color_).PassAs<LayerImpl>();
 }
 
 void ScrollbarLayerImpl::PushPropertiesTo(LayerImpl* layer) {
@@ -65,6 +69,8 @@ void ScrollbarLayerImpl::PushPropertiesTo(LayerImpl* layer) {
 
   ScrollbarLayerImpl* scrollbar_layer = static_cast<ScrollbarLayerImpl*>(layer);
 
+  scrollbar_layer->set_is_solid_color(is_solid_color_);
+
   scrollbar_layer->set_thumb_thickness(thumb_thickness_);
   scrollbar_layer->set_thumb_length(thumb_length_);
   scrollbar_layer->set_track_start(track_start_);
@@ -78,7 +84,7 @@ bool ScrollbarLayerImpl::WillDraw(DrawMode draw_mode,
                                   ResourceProvider* resource_provider) {
   LayerImpl::WillDraw(draw_mode, resource_provider);
   return draw_mode != DRAW_MODE_RESOURCELESS_SOFTWARE ||
-         layer_tree_impl()->settings().solid_color_scrollbars;
+         IsSolidColor();
 }
 
 void ScrollbarLayerImpl::AppendQuads(QuadSink* quad_sink,
@@ -96,7 +102,7 @@ void ScrollbarLayerImpl::AppendQuads(QuadSink* quad_sink,
 
   gfx::Rect thumb_quad_rect = ComputeThumbQuadRect();
 
-  if (layer_tree_impl()->settings().solid_color_scrollbars) {
+  if (IsSolidColor()) {
     scoped_ptr<SolidColorDrawQuad> quad = SolidColorDrawQuad::Create();
     quad->SetNew(shared_quad_state,
                  thumb_quad_rect,
@@ -150,6 +156,16 @@ ScrollbarOrientation ScrollbarLayerImpl::Orientation() const {
   return orientation_;
 }
 
+bool ScrollbarLayerImpl::IsSolidColor() const {
+  return is_solid_color_ ||
+         (layer_tree_impl() &&

[aelias_OOO_until_Jul13, 2013/06/21 23:34:35]

DCHECK(layer_tree_impl()).  (Or you could just get rid of the branch on this
side by pushing the value of IsSolidColor() in PushPropertiesTo()).

[wjmaclean, 2013/06/24 14:06:41]

I thought about pushing it as a property, though I wasn't sure if we'd ever want
to distinguish (at some later time) between a layer that was created "solid"
from one that just picks up the property.

I'll change it so we push the value over.

+          layer_tree_impl()->settings().force_solid_color_scrollbars);
+}
+
+void ScrollbarLayerImpl::set_is_solid_color(bool is_solid_color) {
+  is_solid_color_ = is_solid_color;
+}
+
 float ScrollbarLayerImpl::CurrentPos() const {
   return current_pos_;
 }
@@ -234,7 +250,7 @@ gfx::Rect ScrollbarLayerImpl::ComputeThumbQuadRect() const {
   if (orientation_ == VERTICAL)
     track_length += vertical_adjust_;
 
-  if (layer_tree_impl()->settings().solid_color_scrollbars) {
+  if (IsSolidColor()) {
     thumb_length = std::max(
         static_cast<int>(visible_to_total_length_ratio_ * track_length),
         thumb_thickness_);