cc: Simplify the logic for deciding to update tile priorities.

cc/picture_layer_impl.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/picture_layer_impl.h"
 
 #include "base/time.h"
 #include "cc/append_quads_data.h"
 #include "cc/checkerboard_draw_quad.h"
 #include "cc/debug_border_draw_quad.h"
@@ skipping 198 matching lines @@
   // better scheme would be to maintain a tighter visibleContentRect for the
   // finer tilings.
   CleanUpTilingsOnActiveLayer(seen_tilings);
 }
 
 void PictureLayerImpl::dumpLayerProperties(std::string*, int indent) const {
   // TODO(enne): implement me
 }
 
 void PictureLayerImpl::updateTilePriorities() {
+  if (!tilings_->num_tilings())
+    return;
+
   int current_source_frame_number = layerTreeImpl()->source_frame_number();
   double current_frame_time =
       (layerTreeImpl()->CurrentFrameTime() - base::TimeTicks()).InSecondsF();
 
+  bool has_tiling_that_needs_update = false;
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+    if (tilings_->tiling_at(i)->needs_update_tile_priorities(
+            current_source_frame_number, current_frame_time))
+      has_tiling_that_needs_update = true;
+  }
+  if (!has_tiling_that_needs_update)
+    return;
+
   gfx::Transform current_screen_space_transform =
       screenSpaceTransform();
 
   gfx::Rect viewport_in_content_space;
   gfx::Transform screenToLayer(gfx::Transform::kSkipInitialization);
   if (screenSpaceTransform().GetInverse(&screenToLayer)) {
     gfx::Rect device_viewport(layerTreeImpl()->device_viewport_size());
     viewport_in_content_space = gfx::ToEnclosingRect(
         MathUtil::projectClippedRect(screenToLayer, device_viewport));
   }
@@ skipping 264 matching lines @@
     }
   }
 
   return missing_region.IsEmpty();
 }
 
 PictureLayerTiling* PictureLayerImpl::AddTiling(float contents_scale) {
   DCHECK(contents_scale >= layerTreeImpl()->settings().minimumContentsScale);
 
   PictureLayerTiling* tiling = tilings_->AddTiling(contents_scale);
+  layerTreeImpl()->set_needs_update_tile_priorities();
 
   const Region& recorded = pile_->recorded_region();
   DCHECK(!recorded.IsEmpty());
 
   for (Region::Iterator iter(recorded); iter.has_rect(); iter.next())
     tiling->CreateTilesFromLayerRect(iter.rect());
 
   PictureLayerImpl* twin =
       layerTreeImpl()->IsPendingTree() ? ActiveTwin() : PendingTwin();
   if (!twin)
@@ skipping 210 matching lines @@
   return twin;
 }
 
 void PictureLayerImpl::getDebugBorderProperties(
     SkColor* color, float* width) const {
   *color = DebugColors::TiledContentLayerBorderColor();
   *width = DebugColors::TiledContentLayerBorderWidth(layerTreeImpl());
 }
 
 }  // namespace cc