Revert 253606 "Revert 251238 "cc: Clean up iterator template to ..."

> Revert 251238 "cc: Clean up iterator template to only take 1 par..."
> 
> Speculative revert to see if this affects memory stomping behaviours.
> 
> > cc: Clean up iterator template to only take 1 parameter.
> > 
> > LayerIterator takes 4 parameters. One is the FrontToBack ordering
> > but that is now the only option. The other 3 are for the type of layers,
> > render surfaces, and the render surface layer list. The latter two are
> > now already available as typedefs off of Layer and LayerImpl, so we
> > only need Layer/LayerImpl in the template arguments.
> > 
> > R=enne
> > BUG=YAK
> > 
> > Review URL: https://codereview.chromium.org/156603005
> 
> TBR=danakj@chromium.org
> 
> Review URL: https://codereview.chromium.org/181783004

TBR=danakj@chromium.org

Review URL: https://codereview.chromium.org/182343002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253610 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 97 insertions, 246 deletions

diff --git a/cc/cc.gyp b/cc/cc.gyp
index 3ebe1d4d..0b3308d 100644
--- a/cc/cc.gyp
+++ b/cc/cc.gyp
@@ -162,7 +162,6 @@
         'layers/layer_client.h',
         'layers/layer_impl.cc',
         'layers/layer_impl.h',
-        'layers/layer_iterator.cc',
         'layers/layer_iterator.h',
         'layers/layer_lists.cc',
         'layers/layer_lists.h',
diff --git a/cc/debug/debug_rect_history.cc b/cc/debug/debug_rect_history.cc
index 2f01f4a..4241823 100644
--- a/cc/debug/debug_rect_history.cc
+++ b/cc/debug/debug_rect_history.cc
@@ -238,10 +238,7 @@ void DebugRectHistory::SaveNonFastScrollableRectsCallback(LayerImpl* layer) {
 
 void DebugRectHistory::SaveLayerAnimationBoundsRects(
     const LayerImplList& render_surface_layer_list) {
-  typedef LayerIterator<LayerImpl,
-                        LayerImplList,
-                        RenderSurfaceImpl,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
+  typedef LayerIterator<LayerImpl> LayerIteratorType;
   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list);
   for (LayerIteratorType it =
            LayerIteratorType::Begin(&render_surface_layer_list);
diff --git a/cc/layers/layer_iterator.cc b/cc/layers/layer_iterator.cc
deleted file mode 100644
index a52c3f1..0000000
--- a/cc/layers/layer_iterator.cc
+++ /dev/null
@@ -1,130 +0,0 @@
-// 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/layer_iterator.h"
-
-#include <vector>
-
-#include "cc/layers/layer.h"
-#include "cc/layers/layer_impl.h"
-#include "cc/layers/render_surface.h"
-#include "cc/layers/render_surface_impl.h"
-
-namespace cc {
-
-template <typename LayerType,
-          typename LayerList,
-          typename RenderSurfaceType,
-          typename ActionType>
-void LayerIteratorActions::FrontToBack::Begin(
-    LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
-  it->target_render_surface_layer_index_ = 0;
-  it->current_layer_index_ = it->target_render_surface_children().size() - 1;
-  GoToHighestInSubtree(it);
-}
-
-template <typename LayerType,
-          typename LayerList,
-          typename RenderSurfaceType,
-          typename ActionType>
-void LayerIteratorActions::FrontToBack::End(
-    LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
-  it->target_render_surface_layer_index_ =
-      LayerIteratorValue::kInvalidTargetRenderSurfaceLayerIndex;
-  it->current_layer_index_ = 0;
-}
-
-template <typename LayerType,
-          typename LayerList,
-          typename RenderSurfaceType,
-          typename ActionType>
-void LayerIteratorActions::FrontToBack::Next(
-    LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
-  // Moves to the previous layer in the current RS layer list.
-  // Then we check if the new current layer has its own RS,
-  // in which case there are things in that RS layer list that are higher,
-  // so we find the highest layer in that subtree.
-  // If we move back past the front of the list,
-  // we jump up to the previous RS layer list, picking up again where we
-  // had previously recursed into the current RS layer list.
-
-  if (!it->current_layer_represents_target_render_surface()) {
-    // Subtracting one here will eventually cause the current layer
-    // to become that layer representing the target render surface.
-    --it->current_layer_index_;
-    GoToHighestInSubtree(it);
-  } else {
-    while (it->current_layer_represents_target_render_surface()) {
-      if (!it->target_render_surface_layer_index_) {
-        // End of the list
-        it->target_render_surface_layer_index_ =
-            LayerIteratorValue::kInvalidTargetRenderSurfaceLayerIndex;
-        it->current_layer_index_ = 0;
-        return;
-      }
-      it->target_render_surface_layer_index_ = it->target_render_surface()
-          ->target_render_surface_layer_index_history_;
-      it->current_layer_index_ =
-          it->target_render_surface()->current_layer_index_history_;
-    }
-  }
-}
-
-template <typename LayerType,
-          typename LayerList,
-          typename RenderSurfaceType,
-          typename ActionType>
-void LayerIteratorActions::FrontToBack::GoToHighestInSubtree(
-    LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it) {
-  if (it->current_layer_represents_target_render_surface())
-    return;
-  while (it->current_layer_represents_contributing_render_surface()) {
-    // Save where we were in the current target surface, move to the next one,
-    // and save the target surface that we came from there
-    // so we can go back to it.
-    it->target_render_surface()->current_layer_index_history_ =
-        it->current_layer_index_;
-    int previous_target_render_surface_layer =
-        it->target_render_surface_layer_index_;
-
-    for (LayerType* layer = it->current_layer();
-         it->target_render_surface_layer() != layer;
-         ++it->target_render_surface_layer_index_) {
-    }
-    it->current_layer_index_ = it->target_render_surface_children().size() - 1;
-
-    it->target_render_surface()->target_render_surface_layer_index_history_ =
-        previous_target_render_surface_layer;
-  }
-}
-
-// Declare each of the above functions for Layer and LayerImpl classes
-// so that they are linked.
-template CC_EXPORT void LayerIteratorActions::FrontToBack::Next(
-    LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
-        it);
-template CC_EXPORT void LayerIteratorActions::FrontToBack::End(
-    LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
-        it);
-template CC_EXPORT void LayerIteratorActions::FrontToBack::Begin(
-    LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
-        it);
-template CC_EXPORT void LayerIteratorActions::FrontToBack::GoToHighestInSubtree(
-    LayerIterator<Layer, RenderSurfaceLayerList, RenderSurface, FrontToBack>*
-        it);
-
-template CC_EXPORT void LayerIteratorActions::FrontToBack::Next(
-    LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
-        it);
-template CC_EXPORT void LayerIteratorActions::FrontToBack::End(
-    LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
-        it);
-template CC_EXPORT void LayerIteratorActions::FrontToBack::Begin(
-    LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
-        it);
-template CC_EXPORT void LayerIteratorActions::FrontToBack::GoToHighestInSubtree(
-    LayerIterator<LayerImpl, LayerImplList, RenderSurfaceImpl, FrontToBack>*
-        it);
-
-}  // namespace cc
diff --git a/cc/layers/layer_iterator.h b/cc/layers/layer_iterator.h
index 5b13273..f929eb6 100644
--- a/cc/layers/layer_iterator.h
+++ b/cc/layers/layer_iterator.h
@@ -5,7 +5,6 @@
 #ifndef CC_LAYERS_LAYER_ITERATOR_H_
 #define CC_LAYERS_LAYER_ITERATOR_H_
 
-#include "base/memory/ref_counted.h"
 #include "cc/base/cc_export.h"
 #include "cc/trees/layer_tree_host_common.h"
 
@@ -19,11 +18,7 @@ namespace cc {
 //
 // void DoStuffOnLayers(
 //     const RenderSurfaceLayerList& render_surface_layer_list) {
-//   typedef LayerIterator<Layer,
-//                         RenderSurfaceLayerList,
-//                         RenderSurface,
-//                         LayerIteratorActions::FrontToBack>
-//       LayerIteratorType;
+//   typedef LayerIterator<Layer> LayerIteratorType;
 //
 //   LayerIteratorType end =
 //       LayerIteratorType::End(&render_surface_layer_list);
@@ -105,15 +100,11 @@ template <typename LayerType> struct LayerIteratorPosition {
 
 // An iterator class for walking over layers in the
 // RenderSurface-Layer tree.
-template <typename LayerType,
-          typename LayerList,
-          typename RenderSurfaceType,
-          typename IteratorActionType>
+template <typename LayerType>
 class LayerIterator {
-  typedef LayerIterator<LayerType,
-                        LayerList,
-                        RenderSurfaceType,
-                        IteratorActionType> LayerIteratorType;
+  typedef LayerIterator<LayerType> LayerIteratorType;
+  typedef typename LayerType::RenderSurfaceListType LayerList;
+  typedef typename LayerType::RenderSurfaceType RenderSurfaceType;
 
  public:
   LayerIterator() : render_surface_layer_list_(NULL) {}
@@ -126,7 +117,7 @@ class LayerIterator {
   }
 
   LayerIteratorType& operator++() {
-    actions_.Next(this);
+    MoveToNext();
     return *this;
   }
   bool operator==(const LayerIterator& other) const {
@@ -176,15 +167,81 @@ class LayerIterator {
     for (size_t i = 0; i < render_surface_layer_list->size(); ++i) {
       if (!render_surface_layer_list->at(i)->render_surface()) {
         NOTREACHED();
-        actions_.End(this);
+        MoveToEnd();
         return;
       }
     }
 
     if (start && !render_surface_layer_list->empty())
-      actions_.Begin(this);
+      MoveToBegin();
     else
-      actions_.End(this);
+      MoveToEnd();
+  }
+
+  void MoveToBegin() {
+    target_render_surface_layer_index_ = 0;
+    current_layer_index_ = target_render_surface_children().size() - 1;
+    MoveToHighestInSubtree();
+  }
+
+  void MoveToEnd() {
+    target_render_surface_layer_index_ =
+        LayerIteratorValue::kInvalidTargetRenderSurfaceLayerIndex;
+    current_layer_index_ = 0;
+  }
+
+  void MoveToNext() {
+    // Moves to the previous layer in the current RS layer list.
+    // Then we check if the new current layer has its own RS,
+    // in which case there are things in that RS layer list that are higher,
+    // so we find the highest layer in that subtree.
+    // If we move back past the front of the list,
+    // we jump up to the previous RS layer list, picking up again where we
+    // had previously recursed into the current RS layer list.
+
+    if (!current_layer_represents_target_render_surface()) {
+      // Subtracting one here will eventually cause the current layer
+      // to become that layer representing the target render surface.
+      --current_layer_index_;
+      MoveToHighestInSubtree();
+    } else {
+      while (current_layer_represents_target_render_surface()) {
+        if (!target_render_surface_layer_index_) {
+          // End of the list.
+          target_render_surface_layer_index_ =
+              LayerIteratorValue::kInvalidTargetRenderSurfaceLayerIndex;
+          current_layer_index_ = 0;
+          return;
+        }
+        target_render_surface_layer_index_ =
+            target_render_surface()->target_render_surface_layer_index_history_;
+        current_layer_index_ =
+            target_render_surface()->current_layer_index_history_;
+      }
+    }
+  }
+
+  void MoveToHighestInSubtree() {
+    if (current_layer_represents_target_render_surface())
+      return;
+    while (current_layer_represents_contributing_render_surface()) {
+      // Save where we were in the current target surface, move to the next one,
+      // and save the target surface that we came from there
+      // so we can go back to it.
+      target_render_surface()->current_layer_index_history_ =
+          current_layer_index_;
+      int previous_target_render_surface_layer =
+          target_render_surface_layer_index_;
+
+      for (LayerType* layer = current_layer();
+           target_render_surface_layer() != layer;
+           ++target_render_surface_layer_index_) {
+      }
+      current_layer_index_ = target_render_surface_children().size() - 1;
+
+      target_render_surface()->target_render_surface_layer_index_history_ =
+          previous_target_render_surface_layer;
+    }
   }
 
   inline LayerType* current_layer() const {
@@ -209,7 +266,6 @@ class LayerIterator {
     return target_render_surface()->layer_list();
   }
 
-  IteratorActionType actions_;
   const LayerList* render_surface_layer_list_;
 
   // The iterator's current position.
@@ -228,44 +284,6 @@ class LayerIterator {
   // the target surface, this is done by setting the current_layerIndex
   // to a value of LayerIteratorValue::LayerRepresentingTargetRenderSurface.
   int current_layer_index_;
-
-  friend struct LayerIteratorActions;
-};
-
-// Orderings for iterating over the RenderSurface-Layer tree.
-struct CC_EXPORT LayerIteratorActions {
-  // Walks layers sorted by z-order from front to back
-  class CC_EXPORT FrontToBack {
-   public:
-    template <typename LayerType,
-              typename LayerList,
-              typename RenderSurfaceType,
-              typename ActionType>
-    void Begin(
-        LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it);
-
-    template <typename LayerType,
-              typename LayerList,
-              typename RenderSurfaceType,
-              typename ActionType>
-    void End(
-        LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it);
-
-    template <typename LayerType,
-              typename LayerList,
-              typename RenderSurfaceType,
-              typename ActionType>
-    void Next(
-        LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it);
-
-   private:
-    template <typename LayerType,
-              typename LayerList,
-              typename RenderSurfaceType,
-              typename ActionType>
-    void GoToHighestInSubtree(
-        LayerIterator<LayerType, LayerList, RenderSurfaceType, ActionType>* it);
-  };
 };
 
 }  // namespace cc
diff --git a/cc/layers/layer_iterator_unittest.cc b/cc/layers/layer_iterator_unittest.cc
index c781d28..61d7a61 100644
--- a/cc/layers/layer_iterator_unittest.cc
+++ b/cc/layers/layer_iterator_unittest.cc
@@ -50,10 +50,7 @@ class TestLayer : public Layer {
   EXPECT_EQ(contrib, layer->count_representing_contributing_surface_);         \
   EXPECT_EQ(itself, layer->count_representing_itself_);
 
-typedef LayerIterator<Layer,
-                      RenderSurfaceLayerList,
-                      RenderSurface,
-                      LayerIteratorActions::FrontToBack> FrontToBack;
+typedef LayerIterator<Layer> FrontToBack;
 
 void ResetCounts(RenderSurfaceLayerList* render_surface_layer_list) {
   for (unsigned surface_index = 0;
diff --git a/cc/layers/render_surface.h b/cc/layers/render_surface.h
index b0da4e9..ace787a 100644
--- a/cc/layers/render_surface.h
+++ b/cc/layers/render_surface.h
@@ -19,6 +19,8 @@
 namespace cc {
 
 class Layer;
+template <typename LayerType>
+class LayerIterator;
 
 class CC_EXPORT RenderSurface {
  public:
@@ -112,7 +114,7 @@ class CC_EXPORT RenderSurface {
   }
 
  private:
-  friend struct LayerIteratorActions;
+  friend class LayerIterator<Layer>;
 
   Layer* owning_layer_;
 
diff --git a/cc/layers/render_surface_impl.h b/cc/layers/render_surface_impl.h
index d6ab409..8cbc4fe 100644
--- a/cc/layers/render_surface_impl.h
+++ b/cc/layers/render_surface_impl.h
@@ -25,6 +25,8 @@ class DelegatedRendererLayerImpl;
 class QuadSink;
 class RenderPassSink;
 class LayerImpl;
+template <typename LayerType>
+class LayerIterator;
 
 struct AppendQuadsData;
 
@@ -174,7 +176,7 @@ class CC_EXPORT RenderSurfaceImpl {
   int target_render_surface_layer_index_history_;
   int current_layer_index_history_;
 
-  friend struct LayerIteratorActions;
+  friend class LayerIterator<LayerImpl>;
 
   DISALLOW_COPY_AND_ASSIGN(RenderSurfaceImpl);
 };
diff --git a/cc/trees/layer_tree_host.cc b/cc/trees/layer_tree_host.cc
index bbcdee4..5972a9f 100644
--- a/cc/trees/layer_tree_host.cc
+++ b/cc/trees/layer_tree_host.cc
@@ -887,12 +887,8 @@ void LayerTreeHost::SetPrioritiesForSurfaces(size_t surface_memory_bytes) {
 
 void LayerTreeHost::SetPrioritiesForLayers(
     const RenderSurfaceLayerList& update_list) {
-  typedef LayerIterator<Layer,
-                        RenderSurfaceLayerList,
-                        RenderSurface,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
-
   PriorityCalculator calculator;
+  typedef LayerIterator<Layer> LayerIteratorType;
   LayerIteratorType end = LayerIteratorType::End(&update_list);
   for (LayerIteratorType it = LayerIteratorType::Begin(&update_list);
        it != end;
@@ -989,13 +985,6 @@ void LayerTreeHost::PaintLayerContents(
     ResourceUpdateQueue* queue,
     bool* did_paint_content,
     bool* need_more_updates) {
-  // Use FrontToBack to allow for testing occlusion and performing culling
-  // during the tree walk.
-  typedef LayerIterator<Layer,
-                        RenderSurfaceLayerList,
-                        RenderSurface,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
-
   bool record_metrics_for_frame =
       settings_.show_overdraw_in_tracing &&
       base::debug::TraceLog::GetInstance() &&
@@ -1010,6 +999,9 @@ void LayerTreeHost::PaintLayerContents(
 
   in_paint_layer_contents_ = true;
 
+  // Iterates front-to-back to allow for testing occlusion and performing
+  // culling during the tree walk.
+  typedef LayerIterator<Layer> LayerIteratorType;
   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list);
   for (LayerIteratorType it =
            LayerIteratorType::Begin(&render_surface_layer_list);
diff --git a/cc/trees/layer_tree_host_common.cc b/cc/trees/layer_tree_host_common.cc
index 587a285..ddee393 100644
--- a/cc/trees/layer_tree_host_common.cc
+++ b/cc/trees/layer_tree_host_common.cc
@@ -2324,12 +2324,8 @@ LayerImpl* LayerTreeHostCommon::FindLayerThatIsHitByPoint(
     const LayerImplList& render_surface_layer_list) {
   LayerImpl* found_layer = NULL;
 
-  typedef LayerIterator<LayerImpl,
-                        LayerImplList,
-                        RenderSurfaceImpl,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
+  typedef LayerIterator<LayerImpl> LayerIteratorType;
   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list);
-
   for (LayerIteratorType
            it = LayerIteratorType::Begin(&render_surface_layer_list);
        it != end;
diff --git a/cc/trees/layer_tree_host_impl.cc b/cc/trees/layer_tree_host_impl.cc
index d090ddc..e8155dd 100644
--- a/cc/trees/layer_tree_host_impl.cc
+++ b/cc/trees/layer_tree_host_impl.cc
@@ -762,12 +762,9 @@ DrawSwapReadbackResult::DrawResult LayerTreeHostImpl::CalculateRenderPasses(
         &frame->non_occluding_screen_space_rects);
   }
 
-  // Add quads to the Render passes in FrontToBack order to allow for testing
+  // Add quads to the Render passes in front-to-back order to allow for testing
   // occlusion and performing culling during the tree walk.
-  typedef LayerIterator<LayerImpl,
-                        LayerImplList,
-                        RenderSurfaceImpl,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
+  typedef LayerIterator<LayerImpl> LayerIteratorType;
 
   // Typically when we are missing a texture and use a checkerboard quad, we
   // still draw the frame. However when the layer being checkerboarded is moving
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index 99129ee..d7e4107 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -482,10 +482,7 @@ void LayerTreeImpl::UpdateDrawProperties() {
     // LayerIterator is used here instead of CallFunctionForSubtree to only
     // UpdateTilePriorities on layers that will be visible (and thus have valid
     // draw properties) and not because any ordering is required.
-    typedef LayerIterator<LayerImpl,
-                          LayerImplList,
-                          RenderSurfaceImpl,
-                          LayerIteratorActions::FrontToBack> LayerIteratorType;
+    typedef LayerIterator<LayerImpl> LayerIteratorType;
     LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
     for (LayerIteratorType it =
              LayerIteratorType::Begin(&render_surface_layer_list_);
@@ -739,10 +736,7 @@ scoped_ptr<base::Value> LayerTreeImpl::AsValue() const {
   state->Set("root_layer", root_layer_->AsValue().release());
 
   scoped_ptr<base::ListValue> render_surface_layer_list(new base::ListValue());
-  typedef LayerIterator<LayerImpl,
-                        LayerImplList,
-                        RenderSurfaceImpl,
-                        LayerIteratorActions::FrontToBack> LayerIteratorType;
+  typedef LayerIterator<LayerImpl> LayerIteratorType;
   LayerIteratorType end = LayerIteratorType::End(&render_surface_layer_list_);
   for (LayerIteratorType it = LayerIteratorType::Begin(
            &render_surface_layer_list_); it != end; ++it) {
diff --git a/cc/trees/occlusion_tracker_perftest.cc b/cc/trees/occlusion_tracker_perftest.cc
index 86cb4e6..f4a2faf 100644
--- a/cc/trees/occlusion_tracker_perftest.cc
+++ b/cc/trees/occlusion_tracker_perftest.cc
@@ -91,12 +91,8 @@ TEST_F(OcclusionTrackerPerfTest, UnoccludedContentRect_FullyOccluded) {
   ASSERT_EQ(1u, rsll.size());
   EXPECT_EQ(1u, rsll[0]->render_surface()->layer_list().size());
 
-  typedef LayerIterator<LayerImpl,
-                        LayerImpl::LayerListType,
-                        LayerImpl::RenderSurfaceType,
-                        LayerIteratorActions::FrontToBack> IteratorType;
-  IteratorType begin = IteratorType::Begin(&rsll);
-  IteratorType end = IteratorType::End(&rsll);
+  LayerIterator<LayerImpl> begin = LayerIterator<LayerImpl>::Begin(&rsll);
+  LayerIterator<LayerImpl> end = LayerIterator<LayerImpl>::End(&rsll);
 
   LayerIteratorPosition<LayerImpl> pos = begin;
 
diff --git a/cc/trees/occlusion_tracker_unittest.cc b/cc/trees/occlusion_tracker_unittest.cc
index 81377f6..3e4ff5b 100644
--- a/cc/trees/occlusion_tracker_unittest.cc
+++ b/cc/trees/occlusion_tracker_unittest.cc
@@ -122,10 +122,7 @@ struct OcclusionTrackerTestMainThreadTypes {
   typedef TestContentLayer ContentLayerType;
   typedef scoped_refptr<Layer> LayerPtrType;
   typedef scoped_refptr<ContentLayerType> ContentLayerPtrType;
-  typedef LayerIterator<Layer,
-                        RenderSurfaceLayerList,
-                        RenderSurface,
-                        LayerIteratorActions::FrontToBack> TestLayerIterator;
+  typedef LayerIterator<Layer> TestLayerIterator;
   typedef OcclusionTracker OcclusionTrackerType;
 
   static LayerPtrType CreateLayer(HostType*  host) { return Layer::Create(); }
@@ -155,10 +152,7 @@ struct OcclusionTrackerTestImplThreadTypes {
   typedef TestContentLayerImpl ContentLayerType;
   typedef scoped_ptr<LayerImpl> LayerPtrType;
   typedef scoped_ptr<ContentLayerType> ContentLayerPtrType;
-  typedef LayerIterator<LayerImpl,
-                        LayerImplList,
-                        RenderSurfaceImpl,
-                        LayerIteratorActions::FrontToBack> TestLayerIterator;
+  typedef LayerIterator<LayerImpl> TestLayerIterator;
   typedef OcclusionTrackerImpl OcclusionTrackerType;
 
   static LayerPtrType CreateLayer(HostType* host) {
diff --git a/cc/trees/quad_culler_unittest.cc b/cc/trees/quad_culler_unittest.cc
index 9a5b562..ee97319 100644
--- a/cc/trees/quad_culler_unittest.cc
+++ b/cc/trees/quad_culler_unittest.cc
@@ -39,10 +39,7 @@ class TestOcclusionTrackerImpl
   DISALLOW_COPY_AND_ASSIGN(TestOcclusionTrackerImpl);
 };
 
-typedef LayerIterator<LayerImpl,
-                      LayerImplList,
-                      RenderSurfaceImpl,
-                      LayerIteratorActions::FrontToBack> LayerIteratorType;
+typedef LayerIterator<LayerImpl> LayerIteratorType;
 
 class QuadCullerTest : public testing::Test {
  public: