Remove sparsity tolerance check when considering squashing layers

sky/engine/core/rendering/compositing/CompositingLayerAssigner.cpp

Index: sky/engine/core/rendering/compositing/CompositingLayerAssigner.cpp
diff --git a/sky/engine/core/rendering/compositing/CompositingLayerAssigner.cpp b/sky/engine/core/rendering/compositing/CompositingLayerAssigner.cpp
index 0d24cab737f30d6f5567dfb14392d6765c24e785..5741a53408da4af214f92df6deef92fb50d56957 100644
--- a/sky/engine/core/rendering/compositing/CompositingLayerAssigner.cpp
+++ b/sky/engine/core/rendering/compositing/CompositingLayerAssigner.cpp
@@ -32,10 +32,6 @@
 
 namespace blink {
 
-// We will only allow squashing if the bbox-area:squashed-area doesn't exceed
-// the ratio |gSquashingSparsityTolerance|:1.
-static uint64_t gSquashingSparsityTolerance = 6;
-
 CompositingLayerAssigner::CompositingLayerAssigner(RenderLayerCompositor* compositor)
     : m_compositor(compositor)
     , m_layerSquashingEnabled(compositor->layerSquashingEnabled())
@@ -70,16 +66,6 @@ void CompositingLayerAssigner::SquashingState::updateSquashingStateForNewMapping
     haveAssignedBackingsToEntireSquashingLayerSubtree = false;
 }
 
-bool CompositingLayerAssigner::squashingWouldExceedSparsityTolerance(const RenderLayer* candidate, const CompositingLayerAssigner::SquashingState& squashingState)
-{
-    IntRect bounds = candidate->clippedAbsoluteBoundingBox();
-    IntRect newBoundingRect = squashingState.boundingRect;
-    newBoundingRect.unite(bounds);
-    const uint64_t newBoundingRectArea = newBoundingRect.size().area();
-    const uint64_t newSquashedArea = squashingState.totalAreaOfSquashedRects + bounds.size().area();
-    return newBoundingRectArea > gSquashingSparsityTolerance * newSquashedArea;
-}
-
 bool CompositingLayerAssigner::needsOwnBacking(const RenderLayer* layer) const
 {
     if (!m_compositor->canBeComposited(layer))
@@ -120,9 +106,6 @@ CompositingReasons CompositingLayerAssigner::getReasonsPreventingSquashing(const
     if (!squashingState.haveAssignedBackingsToEntireSquashingLayerSubtree)
         return CompositingReasonSquashingWouldBreakPaintOrder;
 
-    if (squashingWouldExceedSparsityTolerance(layer, squashingState))
-        return CompositingReasonSquashingSparsityExceeded;
-
     // FIXME: this is not efficient, since it walks up the tree . We should store these values on the CompositingInputsCache.
     ASSERT(squashingState.hasMostRecentMapping);
     const RenderLayer& squashingLayer = squashingState.mostRecentMapping->owningLayer();