Let AreVisibleResourcesReady return correct value for PictureImageLayerImpl

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index fd4a85ae1caa3b84baf979acd5d26efc89d90fb5..8f0b51f76e109f1d265c698a0a219d16b7ee3c33 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -33,10 +33,10 @@ PictureLayerImpl::PictureLayerImpl(LayerTreeImpl* tree_impl, int id)
       is_mask_(false),
       ideal_page_scale_(0.f),
       ideal_device_scale_(0.f),
-      ideal_source_scale_(0.f),
       raster_page_scale_(0.f),
       raster_device_scale_(0.f),
-      raster_source_scale_(0.f),
+      raster_contents_scale_(0.f),
+      low_res_raster_contents_scale_(0.f),
       raster_source_scale_was_animating_(false) {
 }
 
@@ -78,7 +78,7 @@ void PictureLayerImpl::PushPropertiesTo(LayerImpl* base_layer) {
 
   layer_impl->raster_page_scale_ = raster_page_scale_;
   layer_impl->raster_device_scale_ = raster_device_scale_;
-  layer_impl->raster_source_scale_ = raster_source_scale_;
+  layer_impl->raster_contents_scale_ = raster_contents_scale_;
 }
 
 
@@ -282,18 +282,13 @@ void PictureLayerImpl::CalculateContentsScale(
   float min_contents_scale = MinimumContentsScale();
   float min_page_scale = layer_tree_impl()->min_page_scale_factor();
   float min_device_scale = 1.f;
-  float min_source_scale =
-      min_contents_scale / min_page_scale / min_device_scale;
 
   float ideal_page_scale = layer_tree_impl()->total_page_scale_factor();
   float ideal_device_scale = layer_tree_impl()->device_scale_factor();
-  float ideal_source_scale =
-      ideal_contents_scale / ideal_page_scale / ideal_device_scale;
 
   ideal_contents_scale_ = std::max(ideal_contents_scale, min_contents_scale);
   ideal_page_scale_ = ideal_page_scale;
   ideal_device_scale_ = ideal_device_scale;
-  ideal_source_scale_ = std::max(ideal_source_scale, min_source_scale);
 
   ManageTilings(animating_transform_to_screen);
 
@@ -391,7 +386,7 @@ void PictureLayerImpl::SyncFromActiveLayer() {
   if (!DrawsContent()) {
     raster_page_scale_ = 0;
     raster_device_scale_ = 0;
-    raster_source_scale_ = 0;
+    raster_contents_scale_ = 0;
     return;
   }
 
@@ -405,7 +400,7 @@ void PictureLayerImpl::SyncFromActiveLayer() {
 void PictureLayerImpl::SyncFromActiveLayer(const PictureLayerImpl* other) {
   raster_page_scale_ = other->raster_page_scale_;
   raster_device_scale_ = other->raster_device_scale_;
-  raster_source_scale_ = other->raster_source_scale_;
+  raster_contents_scale_ = other->raster_contents_scale_;
 
   // Add synthetic invalidations for any recordings that were dropped.  As
   // tiles are updated to point to this new pile, this will force the dropping
@@ -488,30 +483,19 @@ bool PictureLayerImpl::AreVisibleResourcesReady() const {
 
   const gfx::Rect& rect = visible_content_rect();
 
-  float raster_contents_scale =
-      raster_page_scale_ *
-      raster_device_scale_ *
-      raster_source_scale_;
-
   float min_acceptable_scale =
-      std::min(raster_contents_scale, ideal_contents_scale_);
+      std::min(raster_contents_scale_, ideal_contents_scale_);
 
-  TreePriority tree_priority =
-      layer_tree_impl()->tile_manager()->GlobalState().tree_priority;
+  TreePriority tree_priority = layer_tree_impl()->tile_manager()->GlobalState().tree_priority;
   bool should_force_uploads =
       tree_priority != SMOOTHNESS_TAKES_PRIORITY &&
       layer_tree_impl()->animationRegistrar()->
           active_animation_controllers().empty();
 
   if (PictureLayerImpl* twin = ActiveTwin()) {
-    float twin_raster_contents_scale =
-        twin->raster_page_scale_ *
-        twin->raster_device_scale_ *
-        twin->raster_source_scale_;
-
     min_acceptable_scale = std::min(
         min_acceptable_scale,
-        std::min(twin->ideal_contents_scale_, twin_raster_contents_scale));
+        std::min(twin->ideal_contents_scale_, twin->raster_contents_scale_));
   }
 
   Region missing_region = rect;
@@ -593,7 +577,6 @@ void PictureLayerImpl::ManageTilings(bool animating_transform_to_screen) {
   DCHECK(ideal_contents_scale_);
   DCHECK(ideal_page_scale_);
   DCHECK(ideal_device_scale_);
-  DCHECK(ideal_source_scale_);
 
   if (pile_->recorded_region().IsEmpty())
     return;
@@ -603,13 +586,11 @@ void PictureLayerImpl::ManageTilings(bool animating_transform_to_screen) {
 
   bool change_target_tiling = false;
 
-  if (!raster_page_scale_ || !raster_device_scale_ || !raster_source_scale_)
+  if (!raster_page_scale_ || !raster_device_scale_ || !raster_contents_scale_)

[enne (OOO), 2013/03/23 00:47:32]

I think this is wrong.  The previous check was if the raster source scale
changed which is not the same as raster contents scale.

[Xianzhu, 2013/03/25 16:05:07]

I'm confused. How did the previous check deal with changes of raster source
scale?

[danakj, 2013/03/25 16:44:44]

It seems like you're just getting rid of raster source (i.e. CSS) scale here?

The "contents scale" is meant to be the product of the source*page*device
scales.

     change_target_tiling = true;
 
-  // TODO(danakj): Adjust raster_source_scale_ closer to ideal_source_scale_ at
-  // a throttled rate. Possibly make use of invalidation_.IsEmpty() on pending
-  // tree. This will allow CSS scale changes to get re-rastered at an
-  // appropriate rate.
+  if (ShouldAdjustRasterSourceScale())
+    change_target_tiling = true;
 
   if (is_active_layer) {
     if (raster_source_scale_was_animating_ && !animating_transform_to_screen)
@@ -640,22 +621,16 @@ void PictureLayerImpl::ManageTilings(bool animating_transform_to_screen) {
 
   raster_page_scale_ = ideal_page_scale_;
   raster_device_scale_ = ideal_device_scale_;
-  raster_source_scale_ = ideal_source_scale_;
-
-  float raster_contents_scale;
-  float low_res_raster_contents_scale;
-  CalculateRasterContentsScale(animating_transform_to_screen,
-                               &raster_contents_scale,
-                               &low_res_raster_contents_scale);
+  CalculateRasterContentsScale(animating_transform_to_screen);

[enne (OOO), 2013/03/23 00:47:32]

I like the previous version where rather you had a functional-style function
that computed values rather than a function with side effects.  The former makes
it much obvious here in the caller that raster_contents_scale and
low_res_raster_contents_scale are affected by this function. 

 
   PictureLayerTiling* high_res = NULL;
   PictureLayerTiling* low_res = NULL;
 
   for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
     PictureLayerTiling* tiling = tilings_->tiling_at(i);
-    if (tiling->contents_scale() == raster_contents_scale)
+    if (tiling->contents_scale() == raster_contents_scale_)
       high_res = tiling;
-    if (tiling->contents_scale() == low_res_raster_contents_scale)
+    if (tiling->contents_scale() == low_res_raster_contents_scale_)
       low_res = tiling;
 
     // Reset all tilings to non-ideal until the end of this function.
@@ -663,12 +638,12 @@ void PictureLayerImpl::ManageTilings(bool animating_transform_to_screen) {
   }
 
   if (!high_res) {
-    high_res = AddTiling(raster_contents_scale);
-    if (raster_contents_scale == low_res_raster_contents_scale)
+    high_res = AddTiling(raster_contents_scale_);
+    if (raster_contents_scale_ == low_res_raster_contents_scale_)
       low_res = high_res;
   }
   if (!low_res && low_res != high_res)
-    low_res = AddTiling(low_res_raster_contents_scale);
+    low_res = AddTiling(low_res_raster_contents_scale_);
 
   if (high_res)
     high_res->set_resolution(HIGH_RESOLUTION);
@@ -676,22 +651,28 @@ void PictureLayerImpl::ManageTilings(bool animating_transform_to_screen) {
     low_res->set_resolution(LOW_RESOLUTION);
 }
 
+bool PictureLayerImpl::ShouldAdjustRasterSourceScale() const {
+  // TODO(danakj): Adjust raster source scale closer to ideal source scale at
+  // a throttled rate. Possibly make use of invalidation_.IsEmpty() on pending
+  // tree. This will allow CSS scale changes to get re-rastered at an
+  // appropriate rate.
+  return false;
+}
+
 void PictureLayerImpl::CalculateRasterContentsScale(
-    bool animating_transform_to_screen,
-    float* raster_contents_scale,
-    float* low_res_raster_contents_scale) {
-  *raster_contents_scale = ideal_contents_scale_;
+    bool animating_transform_to_screen) {
+  raster_contents_scale_ = ideal_contents_scale_;
 
   // Don't allow animating CSS scales to drop below 1.
   if (animating_transform_to_screen) {
-    *raster_contents_scale = std::max(
-        *raster_contents_scale, 1.f * ideal_page_scale_ * ideal_device_scale_);
+    raster_contents_scale_ = std::max(
+        raster_contents_scale_, 1.f * ideal_page_scale_ * ideal_device_scale_);
   }
 
   float low_res_factor =
       layer_tree_impl()->settings().low_res_contents_scale_factor;
-  *low_res_raster_contents_scale = std::max(
-      *raster_contents_scale * low_res_factor,
+  low_res_raster_contents_scale_ = std::max(
+      raster_contents_scale_ * low_res_factor,
       MinimumContentsScale());
 }
 
@@ -699,27 +680,19 @@ void PictureLayerImpl::CleanUpTilingsOnActiveLayer(
     std::vector<PictureLayerTiling*> used_tilings) {
   DCHECK(layer_tree_impl()->IsActiveTree());
 
-  float raster_contents_scale =
-      raster_page_scale_ * raster_device_scale_ * raster_source_scale_;
-
   float min_acceptable_high_res_scale = std::min(
-      raster_contents_scale, ideal_contents_scale_);
+      raster_contents_scale_, ideal_contents_scale_);
   float max_acceptable_high_res_scale = std::max(
-      raster_contents_scale, ideal_contents_scale_);
+      raster_contents_scale_, ideal_contents_scale_);
 
   PictureLayerImpl* twin = PendingTwin();
   if (twin) {
-    float twin_raster_contents_scale =
-        twin->raster_page_scale_ *
-        twin->raster_device_scale_ *
-        twin->raster_source_scale_;
-
     min_acceptable_high_res_scale = std::min(
         min_acceptable_high_res_scale,
-        std::min(twin_raster_contents_scale, twin->ideal_contents_scale_));
+        std::min(twin->raster_contents_scale_, twin->ideal_contents_scale_));
     max_acceptable_high_res_scale = std::max(
         max_acceptable_high_res_scale,
-        std::max(twin_raster_contents_scale, twin->ideal_contents_scale_));
+        std::max(twin->raster_contents_scale_, twin->ideal_contents_scale_));
   }
 
   float low_res_factor =