Activate LayerImpl tree with sync+push instead of pointer swap

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"
 #include "cc/debug_colors.h"
 #include "cc/layer_tree_impl.h"
 #include "cc/math_util.h"
 #include "cc/quad_sink.h"
 #include "cc/solid_color_draw_quad.h"
 #include "cc/tile_draw_quad.h"
 #include "ui/gfx/quad_f.h"
 #include "ui/gfx/size_conversions.h"
 
 namespace {
 const float kMaxScaleRatioDuringPinch = 2.0f;
 }
 
 namespace cc {
 
 PictureLayerImpl::PictureLayerImpl(LayerTreeImpl* treeImpl, int id)
     : LayerImpl(treeImpl, id),
-      tilings_(this),
       pile_(PicturePileImpl::Create()),
       last_update_time_(0),
       last_content_scale_(0),
       ideal_contents_scale_(0),
       is_mask_(false) {
 }
 
 PictureLayerImpl::~PictureLayerImpl() {
 }
 
 const char* PictureLayerImpl::layerTypeAsString() const {
   return "PictureLayer";
 }
 
+scoped_ptr<LayerImpl> PictureLayerImpl::createLayerImpl(
+    LayerTreeImpl* treeImpl) {
+  return PictureLayerImpl::create(treeImpl, id()).PassAs<LayerImpl>();
+}
+
+void PictureLayerImpl::CreateTilingSet() {
+  DCHECK(layerTreeImpl()->IsPendingTree());
+  DCHECK(!tilings_);
+  tilings_.reset(new PictureLayerTilingSet(this));
+  tilings_->SetLayerBounds(bounds());
+}
+
+void PictureLayerImpl::TransferTilingSet(scoped_ptr<PictureLayerTilingSet> tilings) {
+  DCHECK(layerTreeImpl()->IsActiveTree());
+  tilings->SetClient(this);
+  tilings_ = tilings.Pass();
+}
+
+void PictureLayerImpl::pushPropertiesTo(LayerImpl* base_layer) {
+  LayerImpl::pushPropertiesTo(base_layer);
+
+  PictureLayerImpl* layer_impl = static_cast<PictureLayerImpl*>(base_layer);
+
+  layer_impl->SetIsMask(is_mask_);
+  layer_impl->TransferTilingSet(tilings_.Pass());
+  layer_impl->pile_ = pile_;
+  pile_ = PicturePileImpl::Create();
+}
+
+
 void PictureLayerImpl::appendQuads(QuadSink& quadSink,
                                    AppendQuadsData& appendQuadsData) {
   const gfx::Rect& rect = visibleContentRect();
   gfx::Rect content_rect(gfx::Point(), contentBounds());
 
   SharedQuadState* sharedQuadState =
       quadSink.useSharedQuadState(createSharedQuadState());
   bool clipped = false;
   gfx::QuadF target_quad = MathUtil::mapQuad(
       drawTransform(),
       gfx::QuadF(rect),
       clipped);
   bool isAxisAlignedInTarget = !clipped && target_quad.IsRectilinear();
   bool useAA = !isAxisAlignedInTarget;
 
   if (showDebugBorders()) {
-    for (PictureLayerTilingSet::Iterator iter(&tilings_,
+    for (PictureLayerTilingSet::Iterator iter(tilings_.get(),
                                               contentsScaleX(),
                                               rect,
                                               ideal_contents_scale_);
          iter;
          ++iter) {
       SkColor color;
       float width;
       if (*iter && iter->GetResourceId()) {
         color = DebugColors::TileBorderColor();
         width = DebugColors::TileBorderWidth(layerTreeImpl());
       } else {
         color = DebugColors::MissingTileBorderColor();
         width = DebugColors::MissingTileBorderWidth(layerTreeImpl());
       }
 
       scoped_ptr<DebugBorderDrawQuad> debugBorderQuad =
           DebugBorderDrawQuad::Create();
       gfx::Rect geometry_rect = iter.geometry_rect();
       debugBorderQuad->SetNew(sharedQuadState, geometry_rect, color, width);
       quadSink.append(debugBorderQuad.PassAs<DrawQuad>(), appendQuadsData);
     }
   }
 
   // Keep track of the tilings that were used so that tilings that are
   // unused can be considered for removal.
   std::vector<PictureLayerTiling*> seen_tilings;
 
-  for (PictureLayerTilingSet::Iterator iter(&tilings_,
+  for (PictureLayerTilingSet::Iterator iter(tilings_.get(),
                                             contentsScaleX(),
                                             rect,
                                             ideal_contents_scale_);
        iter;
        ++iter) {
     ResourceProvider::ResourceId resource = 0;
     if (*iter)
       resource = iter->GetResourceId();
 
     gfx::Rect geometry_rect = iter.geometry_rect();
@@ skipping 57 matching lines @@
       screenSpaceTransform();
   double current_time =
       (base::TimeTicks::Now() - base::TimeTicks()).InSecondsF();
   double time_delta = 0;
   if (last_update_time_ != 0 && last_bounds_ == bounds() &&
       last_content_bounds_ == contentBounds() &&
       last_content_scale_ == contentsScaleX()) {
     time_delta = current_time - last_update_time_;
   }
   WhichTree tree = layerTreeImpl()->IsActiveTree() ? ACTIVE_TREE : PENDING_TREE;
-  tilings_.UpdateTilePriorities(
+  tilings_->UpdateTilePriorities(
       tree,
       layerTreeImpl()->device_viewport_size(),
       last_content_scale_,
       contentsScaleX(),
       last_screen_space_transform_,
       current_screen_space_transform,
       time_delta);
 
   last_screen_space_transform_ = current_screen_space_transform;
   last_update_time_ = current_time;
   last_bounds_ = bounds();
   last_content_bounds_ = contentBounds();
   last_content_scale_ = contentsScaleX();
 }
 
 void PictureLayerImpl::didBecomeActive() {
-  tilings_.DidBecomeActive();
+  LayerImpl::didBecomeActive();
+  tilings_->DidBecomeActive();
 }
 
 void PictureLayerImpl::didLoseOutputSurface() {
-  tilings_.RemoveAllTilings();
+  if (tilings_)
+    tilings_->RemoveAllTilings();
 }
 
 void PictureLayerImpl::calculateContentsScale(
     float ideal_contents_scale,
     float* contents_scale_x,
     float* contents_scale_y,
     gfx::Size* content_bounds) {
   if (!drawsContent()) {
-    DCHECK(!tilings_.num_tilings());
+    DCHECK(!tilings_->num_tilings());
     return;
   }
 
   float min_contents_scale = layerTreeImpl()->settings().minimumContentsScale;
   ideal_contents_scale_ = std::max(ideal_contents_scale, min_contents_scale);
 
   ManageTilings(ideal_contents_scale_);
 
   // The content scale and bounds for a PictureLayerImpl is somewhat fictitious.
   // There are (usually) several tilings at different scales.  However, the
   // content bounds is the (integer!) space in which quads are generated.
   // In order to guarantee that we can fill this integer space with any set of
   // tilings (and then map back to floating point texture coordinates), the
   // contents scale must be at least as large as the largest of the tilings.
   float max_contents_scale = min_contents_scale;
-  for (size_t i = 0; i < tilings_.num_tilings(); ++i) {
-    const PictureLayerTiling* tiling = tilings_.tiling_at(i);
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+    const PictureLayerTiling* tiling = tilings_->tiling_at(i);
     max_contents_scale = std::max(max_contents_scale, tiling->contents_scale());
   }
 
   *contents_scale_x = max_contents_scale;
   *contents_scale_y = max_contents_scale;
   *content_bounds = gfx::ToCeiledSize(
       gfx::ScaleSize(bounds(), max_contents_scale, max_contents_scale));
 }
 
 skia::RefPtr<SkPicture> PictureLayerImpl::getPicture() {
@@ skipping 26 matching lines @@
   // tiles.  This needs to be done last, after setting invalidation and the
   // pile.
   PictureLayerImpl* active_twin = static_cast<PictureLayerImpl*>(
       layerTreeImpl()->FindActiveTreeLayerById(id()));
   if (!active_twin)
     return;
   SyncFromActiveLayer(active_twin);
 }
 
 void PictureLayerImpl::SyncFromActiveLayer(const PictureLayerImpl* other) {
-  tilings_.CloneAll(other->tilings_, invalidation_);
-  DCHECK(bounds() == tilings_.LayerBounds());
+  tilings_->CloneAll(*other->tilings_, invalidation_);
+  DCHECK(bounds() == tilings_->LayerBounds());
 }
 
 void PictureLayerImpl::SyncTiling(
     const PictureLayerTiling* tiling) {
-  tilings_.Clone(tiling, invalidation_);
+  tilings_->Clone(tiling, invalidation_);
 }
 
 void PictureLayerImpl::SetIsMask(bool is_mask) {
   if (is_mask_ == is_mask)
     return;
   is_mask_ = is_mask;
-  tilings_.RemoveAllTiles();
+  tilings_->RemoveAllTiles();
 }
 
 ResourceProvider::ResourceId PictureLayerImpl::contentsResourceId() const {
   gfx::Rect content_rect(gfx::Point(), contentBounds());
   float scale = contentsScaleX();
-  for (PictureLayerTilingSet::Iterator iter(&tilings_,
+  for (PictureLayerTilingSet::Iterator iter(tilings_.get(),
                                             scale,
                                             content_rect,
                                             ideal_contents_scale_);
        iter;
        ++iter) {
     // Mask resource not ready yet.
     if (!*iter || !iter->GetResourceId())
       return 0;
     // Masks only supported if they fit on exactly one tile.
     if (iter.geometry_rect() != content_rect)
       return 0;
     return iter->GetResourceId();
   }
   return 0;
 }
 
 bool PictureLayerImpl::areVisibleResourcesReady() const {
   const gfx::Rect& rect = visibleContentRect();
 
-  for (size_t i = 0; i < tilings_.num_tilings(); ++i) {
-    const PictureLayerTiling* tiling = tilings_.tiling_at(i);
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+    const PictureLayerTiling* tiling = tilings_->tiling_at(i);
 
     // Ignore non-high resolution tilings.
     if (tiling->resolution() != HIGH_RESOLUTION)
       continue;
 
     for (PictureLayerTiling::Iterator iter(tiling,
                                            tiling->contents_scale(),
                                            rect);
          iter;
          ++iter) {
       // Resource not ready yet.
       if (!*iter || !iter->GetResourceId())
         return false;
     }
     return true;
   }
   return false;
 }
 
 PictureLayerTiling* PictureLayerImpl::AddTiling(float contents_scale) {
   if (contents_scale < layerTreeImpl()->settings().minimumContentsScale)
     return NULL;
 
-  PictureLayerTiling* tiling = tilings_.AddTiling(
+  PictureLayerTiling* tiling = tilings_->AddTiling(
       contents_scale,
       TileSize());
 
   // If a new tiling is created on the active tree, sync it to the pending tree
   // so that it can share the same tiles.
   if (layerTreeImpl()->IsPendingTree())
     return tiling;
 
   PictureLayerImpl* pending_twin = static_cast<PictureLayerImpl*>(
       layerTreeImpl()->FindPendingTreeLayerById(id()));
@@ skipping 40 matching lines @@
   float low_res_factor = layerTreeImpl()->settings().lowResContentsScaleFactor;
   float low_res_contents_scale = ideal_contents_scale * low_res_factor;
 
   // Remove any tilings from the pending tree that don't exactly match the
   // contents scale.  The pending tree should always come in crisp.  However,
   // don't do this during a pinch, to avoid throwing away a tiling that should
   // have been kept.
   if (layerTreeImpl()->IsPendingTree() &&
       !layerTreeImpl()->PinchGestureActive()) {
     std::vector<PictureLayerTiling*> remove_list;
-    for (size_t i = 0; i < tilings_.num_tilings(); ++i) {
-      PictureLayerTiling* tiling = tilings_.tiling_at(i);
+    for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+      PictureLayerTiling* tiling = tilings_->tiling_at(i);
       if (tiling->contents_scale() == ideal_contents_scale)
         continue;
       if (tiling->contents_scale() == low_res_contents_scale)
         continue;
       remove_list.push_back(tiling);
     }
 
     for (size_t i = 0; i < remove_list.size(); ++i)
-      tilings_.Remove(remove_list[i]);
+      tilings_->Remove(remove_list[i]);
   }
 
   // Find existing tilings closest to ideal high / low res.
   PictureLayerTiling* high_res = NULL;
   PictureLayerTiling* low_res = NULL;
-  for (size_t i = 0; i < tilings_.num_tilings(); ++i) {
-    PictureLayerTiling* tiling = tilings_.tiling_at(i);
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+    PictureLayerTiling* tiling = tilings_->tiling_at(i);
     if (!high_res || IsCloserToThan(tiling, high_res, ideal_contents_scale))
       high_res = tiling;
     if (!low_res || IsCloserToThan(tiling, low_res, low_res_contents_scale))
       low_res = tiling;
 
     // Reset all tilings to non-ideal until the end of this function.
     tiling->set_resolution(NON_IDEAL_RESOLUTION);
   }
 
   // The active tree always has calcDrawProperties called on it first, and
@@ skipping 23 matching lines @@
   if (high_res)
     high_res->set_resolution(HIGH_RESOLUTION);
   if (low_res && low_res != high_res)
     low_res->set_resolution(LOW_RESOLUTION);
 }
 
 void PictureLayerImpl::CleanUpUnusedTilings(
     std::vector<PictureLayerTiling*> used_tilings) {
   std::vector<PictureLayerTiling*> to_remove;
 
-  for (size_t i = 0; i < tilings_.num_tilings(); ++i) {
-    PictureLayerTiling* tiling = tilings_.tiling_at(i);
+  for (size_t i = 0; i < tilings_->num_tilings(); ++i) {
+    PictureLayerTiling* tiling = tilings_->tiling_at(i);
     // Don't remove the current high or low res tilinig.
     if (tiling->resolution() != NON_IDEAL_RESOLUTION)
       continue;
     if (std::find(used_tilings.begin(), used_tilings.end(), tiling) ==
         used_tilings.end())
       to_remove.push_back(tiling);
   }
 
   for (size_t i = 0; i < to_remove.size(); ++i)
-    tilings_.Remove(to_remove[i]);
+    tilings_->Remove(to_remove[i]);
 }
 
 }  // namespace cc