Get rid of graphics layer anchor points, and replace with transform origin.

cc/trees/layer_tree_host_common.cc

 // Copyright 2011 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/trees/layer_tree_host_common.h"
 
 #include <algorithm>
 
 #include "base/debug/trace_event.h"
 #include "cc/base/math_util.h"
@@ skipping 1633 matching lines @@
   }
 
   bool animating_transform_to_target = layer->TransformIsAnimating();
   bool animating_transform_to_screen = animating_transform_to_target;
   if (layer->parent()) {
     animating_transform_to_target |=
         layer->parent()->draw_transform_is_animating();
     animating_transform_to_screen |=
         layer->parent()->screen_space_transform_is_animating();
   }
-
-  gfx::Size bounds = layer->bounds();
-  gfx::PointF anchor_point = layer->anchor_point();
+  gfx::Point3F transform_origin = layer->transform_origin();
   gfx::Vector2dF scroll_offset = GetEffectiveTotalScrollOffset(layer);
   gfx::PointF position = layer->position() - scroll_offset;
-
   gfx::Transform combined_transform = data_from_ancestor.parent_matrix;
   if (!layer->transform().IsIdentity()) {
-    // LT = Tr[origin] * Tr[origin2anchor]
+    // LT = Tr[origin] * Tr[origin2transformOrigin]
+    combined_transform.Translate3d(position.x() + transform_origin.x(),
+                                   position.y() + transform_origin.y(),
+                                   transform_origin.z());
+    // LT = Tr[origin] * Tr[origin2origin] * M[layer]
+    combined_transform.PreconcatTransform(layer->transform());
+    // LT = Tr[origin] * Tr[origin2origin] * M[layer] *
+    // Tr[transformOrigin2origin]
     combined_transform.Translate3d(
-        position.x() + anchor_point.x() * bounds.width(),
-        position.y() + anchor_point.y() * bounds.height(),
-        layer->anchor_point_z());
-    // LT = Tr[origin] * Tr[origin2anchor] * M[layer]
-    combined_transform.PreconcatTransform(layer->transform());
-    // LT = Tr[origin] * Tr[origin2anchor] * M[layer] * Tr[anchor2origin]
-    combined_transform.Translate3d(-anchor_point.x() * bounds.width(),
-                                   -anchor_point.y() * bounds.height(),
-                                   -layer->anchor_point_z());
+        -transform_origin.x(), -transform_origin.y(), -transform_origin.z());
   } else {
     combined_transform.Translate(position.x(), position.y());
   }
 
   gfx::Vector2dF effective_scroll_delta = GetEffectiveScrollDelta(layer);
   if (!animating_transform_to_target && layer->scrollable() &&
       combined_transform.IsScaleOrTranslation()) {
     // Align the scrollable layer's position to screen space pixels to avoid
     // blurriness.  To avoid side-effects, do this only if the transform is
     // simple.
@@ skipping 560 matching lines @@
         layer->contents_scale_x() / render_surface_sublayer_scale.x(),
         layer->contents_scale_y() / render_surface_sublayer_scale.y());
     render_surface->SetScreenSpaceTransform(screen_space_transform);
 
     if (layer->replica_layer()) {
       gfx::Transform surface_origin_to_replica_origin_transform;
       surface_origin_to_replica_origin_transform.Scale(
           render_surface_sublayer_scale.x(), render_surface_sublayer_scale.y());
       surface_origin_to_replica_origin_transform.Translate(
           layer->replica_layer()->position().x() +
-          layer->replica_layer()->anchor_point().x() * bounds.width(),
+              layer->replica_layer()->transform_origin().x(),
           layer->replica_layer()->position().y() +
-          layer->replica_layer()->anchor_point().y() * bounds.height());
+              layer->replica_layer()->transform_origin().y());
       surface_origin_to_replica_origin_transform.PreconcatTransform(
           layer->replica_layer()->transform());
       surface_origin_to_replica_origin_transform.Translate(
-          -layer->replica_layer()->anchor_point().x() * bounds.width(),
-          -layer->replica_layer()->anchor_point().y() * bounds.height());
+          -layer->replica_layer()->transform_origin().x(),
+          -layer->replica_layer()->transform_origin().y());
       surface_origin_to_replica_origin_transform.Scale(
           1.0 / render_surface_sublayer_scale.x(),
           1.0 / render_surface_sublayer_scale.y());
 
       // Compute the replica's "originTransform" that maps from the replica's
       // origin space to the target surface origin space.
       gfx::Transform replica_origin_transform =
           layer->render_surface()->draw_transform() *
           surface_origin_to_replica_origin_transform;
       render_surface->SetReplicaDrawTransform(replica_origin_transform);
@@ skipping 140 matching lines @@
       inputs->current_render_surface_layer_list_id);
 
   // The dummy layer list should not have been used.
   DCHECK_EQ(0u, dummy_layer_list.size());
   // A root layer render_surface should always exist after
   // CalculateDrawProperties.
   DCHECK(inputs->root_layer->render_surface());
 }
 
 }  // namespace cc