[1/5] Pass transformed rasterization policy from Blink

cc/layers/picture_layer.cc

Index: cc/layers/picture_layer.cc
diff --git a/cc/layers/picture_layer.cc b/cc/layers/picture_layer.cc
index 8ed4c8b768a36055971a4d5a1da27b8d7efeadf8..27ec2d57c1a6f8c7202fd4ad35f51a359b69cb08 100644
--- a/cc/layers/picture_layer.cc
+++ b/cc/layers/picture_layer.cc
@@ -16,6 +16,7 @@
 #include "cc/proto/layer.pb.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
+#include "cc/trees/transform_node.h"
 #include "third_party/skia/include/core/SkPictureRecorder.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 
@@ -59,6 +60,7 @@ void PictureLayer::PushPropertiesTo(LayerImpl* base_layer) {
   DropRecordingSourceContentIfInvalid();
 
   layer_impl->SetNearestNeighbor(picture_layer_inputs_.nearest_neighbor);
+  layer_impl->SetUseTransformedRasterization(UseTransformedRasterization());
 
   // Preserve lcd text settings from the current raster source.
   bool can_use_lcd_text = layer_impl->RasterSourceUsesLCDText();
@@ -198,6 +200,14 @@ void PictureLayer::SetNearestNeighbor(bool nearest_neighbor) {
   SetNeedsCommit();
 }
 
+void PictureLayer::SetAllowTransformedRasterization(bool allowed) {
+  if (picture_layer_inputs_.allow_transformed_rasterization == allowed)
+    return;
+
+  picture_layer_inputs_.allow_transformed_rasterization = allowed;
+  SetNeedsCommit();
+}
+
 bool PictureLayer::HasDrawableContent() const {
   return picture_layer_inputs_.client && Layer::HasDrawableContent();
 }
@@ -262,6 +272,27 @@ void PictureLayer::DropRecordingSourceContentIfInvalid() {
   }
 }
 
+bool PictureLayer::UseTransformedRasterization() const {
+  if (!picture_layer_inputs_.allow_transformed_rasterization)
+    return false;
+
+  const TransformTree &transform_tree = GetLayerTree()->property_trees()->transform_tree;
+  DCHECK(!transform_tree.needs_update());
+  if (transform_tree.Node(transform_tree_index())->to_screen_is_potentially_animated)
+    return false;
+
+  const gfx::Transform& to_screen = transform_tree.ToScreen(transform_tree_index());
+  if (!to_screen.IsScaleOrTranslation())
+    return false;
+
+  float origin_x = to_screen.matrix().getFloat(0, 3) + offset_to_transform_parent().x();
+  float origin_y = to_screen.matrix().getFloat(1, 3) + offset_to_transform_parent().y();
+  if (origin_x - floorf(origin_x) == 0.f && origin_y - floorf(origin_y) == 0.f)
+    return false;
+
+  return true;
+}
+
 const DisplayItemList* PictureLayer::GetDisplayItemList() {
   return picture_layer_inputs_.display_list.get();
 }