Make IsSolidColor() a property on CC scrollbar layers.

cc/layers/scrollbar_layer.cc

 
 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/layers/scrollbar_layer.h"
 
 #include "base/auto_reset.h"
 #include "base/basictypes.h"
 #include "base/debug/trace_event.h"
 #include "cc/layers/scrollbar_layer_impl.h"
 #include "cc/resources/caching_bitmap_content_layer_updater.h"
 #include "cc/resources/layer_painter.h"
 #include "cc/resources/prioritized_resource.h"
 #include "cc/resources/resource_update_queue.h"
 #include "cc/trees/layer_tree_host.h"
 #include "ui/gfx/rect_conversions.h"
 
 namespace cc {
 
 scoped_ptr<LayerImpl> ScrollbarLayer::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return ScrollbarLayerImpl::Create(
-      tree_impl, id(), scrollbar_->Orientation()).PassAs<LayerImpl>();
+      tree_impl, id(), scrollbar_->Orientation(), is_solid_color_)
+      .PassAs<LayerImpl>();
 }
 
 scoped_refptr<ScrollbarLayer> ScrollbarLayer::Create(
     scoped_ptr<Scrollbar> scrollbar,
-    int scroll_layer_id) {
+    int scroll_layer_id,
+    bool is_solid_color) {
   return make_scoped_refptr(new ScrollbarLayer(scrollbar.Pass(),
-                                               scroll_layer_id));
+                                               scroll_layer_id,
+                                               is_solid_color));
 }
 
 ScrollbarLayer::ScrollbarLayer(
     scoped_ptr<Scrollbar> scrollbar,
-    int scroll_layer_id)
+    int scroll_layer_id,
+    bool is_solid_color)
     : scrollbar_(scrollbar.Pass()),
       scroll_layer_id_(scroll_layer_id),
+      is_solid_color_(is_solid_color),
       texture_format_(GL_INVALID_ENUM) {
   if (!scrollbar_->IsOverlay())
     SetShouldScrollOnMainThread(true);
 }
 
 ScrollbarLayer::~ScrollbarLayer() {}
 
 void ScrollbarLayer::SetScrollLayerId(int id) {
   if (id == scroll_layer_id_)
     return;
 
   scroll_layer_id_ = id;
   SetNeedsFullTreeSync();
 }
 
 bool ScrollbarLayer::OpacityCanAnimateOnImplThread() const {
   return scrollbar_->IsOverlay();
 }
 
 ScrollbarOrientation ScrollbarLayer::Orientation() const {
   return scrollbar_->Orientation();
 }
 
+bool ScrollbarLayer::IsSolidColor() const {
+  return is_solid_color_ ||
+         (layer_tree_host() &&

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

Please DCHECK(layer_tree_host()) instead.

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

Actually, the only reason it's there is that there are unit tests that don't set
layer tree host (so they'll crash without this).

[aelias_OOO_until_Jul13, 2013/06/25 06:54:57]

Can we fix the unit tests instead?  I feel this production change is slightly
dangerous.  There's a risk of creating a texture in the interval before the
layer_tree_host is available.

+          layer_tree_host()->settings().force_solid_color_scrollbars);
+}
+
 int ScrollbarLayer::MaxTextureSize() {
   DCHECK(layer_tree_host());
   return layer_tree_host()->GetRendererCapabilities().max_texture_size;
 }
 
 float ScrollbarLayer::ClampScaleToMaxTextureSize(float scale) {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
+  if (IsSolidColor())
     return scale;
 
   // If the scaled content_bounds() is bigger than the max texture size of the
   // device, we need to clamp it by rescaling, since content_bounds() is used
   // below to set the texture size.
   gfx::Size scaled_bounds = ComputeContentBoundsForScale(scale, scale);
   if (scaled_bounds.width() > MaxTextureSize() ||
       scaled_bounds.height() > MaxTextureSize()) {
     if (scaled_bounds.width() > scaled_bounds.height())
       return (MaxTextureSize() - 1) / static_cast<float>(bounds().width());
@@ skipping 18 matching lines @@
       contents_scale_x,
       contents_scale_y,
       content_bounds);
 }
 
 void ScrollbarLayer::PushPropertiesTo(LayerImpl* layer) {
   ContentsScalingLayer::PushPropertiesTo(layer);
 
   ScrollbarLayerImpl* scrollbar_layer = static_cast<ScrollbarLayerImpl*>(layer);
 
-  if (layer_tree_host() &&
-      layer_tree_host()->settings().solid_color_scrollbars) {
+  if (layer_tree_host() && IsSolidColor()) {
     int thickness_override =
         layer_tree_host()->settings().solid_color_scrollbar_thickness_dip;
     if (thickness_override != -1) {
       scrollbar_layer->set_thumb_thickness(thickness_override);
     } else {
       if (Orientation() == HORIZONTAL)
         scrollbar_layer->set_thumb_thickness(bounds().height());
       else
         scrollbar_layer->set_thumb_thickness(bounds().width());
     }
   } else {
     scrollbar_layer->set_thumb_thickness(thumb_thickness_);
   }
   scrollbar_layer->set_thumb_length(thumb_length_);
   if (Orientation() == HORIZONTAL) {
     scrollbar_layer->set_track_start(track_rect_.x());
     scrollbar_layer->set_track_length(track_rect_.width());
   } else {
     scrollbar_layer->set_track_start(track_rect_.y());
     scrollbar_layer->set_track_length(track_rect_.height());
   }
+  scrollbar_layer->set_is_solid_color(IsSolidColor());
 
   if (track_ && track_->texture()->have_backing_texture())
     scrollbar_layer->set_track_resource_id(track_->texture()->resource_id());
   else
     scrollbar_layer->set_track_resource_id(0);
 
   if (thumb_ && thumb_->texture()->have_backing_texture())
     scrollbar_layer->set_thumb_resource_id(thumb_->texture()->resource_id());
   else
     scrollbar_layer->set_thumb_resource_id(0);
@@ skipping 27 matching lines @@
                      gfx::RectF* opaque) OVERRIDE {
     scrollbar_->PaintPart(canvas, part_, content_rect);
   }
 
  private:
   Scrollbar* scrollbar_;
   ScrollbarPart part_;
 };
 
 void ScrollbarLayer::CreateUpdaterIfNeeded() {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
+  if (IsSolidColor())
     return;
 
   texture_format_ =
       layer_tree_host()->GetRendererCapabilities().best_texture_format;
 
   if (!track_updater_.get()) {
     track_updater_ = CachingBitmapContentLayerUpdater::Create(
         scoped_ptr<LayerPainter>(
             new ScrollbarPartPainter(scrollbar_.get(), TRACK))
             .Pass(),
@@ skipping 17 matching lines @@
     thumb_ = thumb_updater_->CreateResource(
         layer_tree_host()->contents_texture_manager());
   }
 }
 
 void ScrollbarLayer::UpdatePart(CachingBitmapContentLayerUpdater* painter,
                                 LayerUpdater::Resource* resource,
                                 gfx::Rect rect,
                                 ResourceUpdateQueue* queue,
                                 RenderingStats* stats) {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
+  if (IsSolidColor())
     return;
 
   // Skip painting and uploading if there are no invalidations and
   // we already have valid texture data.
   if (resource->texture()->have_backing_texture() &&
       resource->texture()->size() == rect.size() &&
       !is_dirty())
     return;
 
   // We should always have enough memory for UI.
@@ skipping 34 matching lines @@
       layer_rect, contents_scale_y(), contents_scale_y());
   // We should never return a rect bigger than the content_bounds().
   gfx::Size clamped_size = expanded_rect.size();
   clamped_size.SetToMin(content_bounds());
   expanded_rect.set_size(clamped_size);
   return expanded_rect;
 }
 
 void ScrollbarLayer::SetTexturePriorities(
     const PriorityCalculator& priority_calc) {
-  if (layer_tree_host()->settings().solid_color_scrollbars)
+  if (IsSolidColor())
     return;
 
   if (content_bounds().IsEmpty())
     return;
   DCHECK_LE(content_bounds().width(), MaxTextureSize());
   DCHECK_LE(content_bounds().height(), MaxTextureSize());
 
   CreateUpdaterIfNeeded();
 
   bool draws_to_root = !render_target()->parent();
   if (track_) {
     track_->texture()->SetDimensions(content_bounds(), texture_format_);
     track_->texture()->set_request_priority(
         PriorityCalculator::UIPriority(draws_to_root));
   }
   if (thumb_) {
     gfx::Size thumb_size = OriginThumbRect().size();
     thumb_->texture()->SetDimensions(thumb_size, texture_format_);
     thumb_->texture()->set_request_priority(
         PriorityCalculator::UIPriority(draws_to_root));
   }
 }
 
 void ScrollbarLayer::Update(ResourceUpdateQueue* queue,
                             const OcclusionTracker* occlusion,
                             RenderingStats* stats) {
   track_rect_ = scrollbar_->TrackRect();
 
-  if (layer_tree_host()->settings().solid_color_scrollbars)
+  if (IsSolidColor())
     return;
 
   {
     base::AutoReset<bool> ignore_set_needs_commit(&ignore_set_needs_commit_,
                                                   true);
     ContentsScalingLayer::Update(queue, occlusion, stats);
   }
 
   dirty_rect_.Union(update_rect_);
   if (content_bounds().IsEmpty())
@@ skipping 33 matching lines @@
     thumb_size = gfx::Size(scrollbar_->ThumbLength(),
                            scrollbar_->ThumbThickness());
   } else {
     thumb_size = gfx::Size(scrollbar_->ThumbThickness(),
                            scrollbar_->ThumbLength());
   }
   return ScrollbarLayerRectToContentRect(gfx::Rect(thumb_size));
 }
 
 }  // namespace cc