Remove malloc of HitTestingTransformState, and instead allocate on the stack.

To do this, use the base::Optional pattern instead of a scoped_refptr.

Bug: 459810

Cq-Include-Trybots: luci.chromium.try:linux_layout_tests_slimming_paint_v2;master.tryserver.blink:linux_trusty_blink_rel
Change-Id: I64ada0722e1e04b1f0402c6d3e9d2ed4879164dd
Reviewed-on: https://chromium-review.googlesource.com/1226072
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Reviewed-by: vmpstr <vmpstr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591445}

third_party/blink/renderer/core/layout/hit_testing_transform_state.h

@@ -26,13 +26,11 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_HIT_TESTING_TRANSFORM_STATE_H_
 #define THIRD_PARTY_BLINK_RENDERER_CORE_LAYOUT_HIT_TESTING_TRANSFORM_STATE_H_
 
-#include "base/memory/scoped_refptr.h"
 #include "third_party/blink/renderer/platform/geometry/float_point.h"
 #include "third_party/blink/renderer/platform/geometry/float_quad.h"
 #include "third_party/blink/renderer/platform/geometry/int_size.h"
 #include "third_party/blink/renderer/platform/transforms/affine_transform.h"
 #include "third_party/blink/renderer/platform/transforms/transformation_matrix.h"
-#include "third_party/blink/renderer/platform/wtf/ref_counted.h"
 
 namespace blink {
 
@@ -42,18 +40,22 @@ namespace blink {
 // removed and replaced with TransformState. There are some minor differences
 // (like the way translate() works slightly differently than move()) so care has
 // to be taken when this is done.
-class HitTestingTransformState : public RefCounted<HitTestingTransformState> {
+class HitTestingTransformState {
  public:
-  static scoped_refptr<HitTestingTransformState> Create(const FloatPoint& p,
-                                                        const FloatQuad& quad,
-                                                        const FloatQuad& area) {
-    return base::AdoptRef(new HitTestingTransformState(p, quad, area));
-  }
+  HitTestingTransformState(const FloatPoint& p,
+                           const FloatQuad& quad,
+                           const FloatQuad& area)
+      : last_planar_point_(p),
+        last_planar_quad_(quad),
+        last_planar_area_(area),
+        accumulating_transform_(false) {}
 
-  static scoped_refptr<HitTestingTransformState> Create(
-      const HitTestingTransformState& other) {
-    return base::AdoptRef(new HitTestingTransformState(other));
-  }
+  HitTestingTransformState(const HitTestingTransformState& other)
+      : last_planar_point_(other.last_planar_point_),
+        last_planar_quad_(other.last_planar_quad_),
+        last_planar_area_(other.last_planar_area_),
+        accumulated_transform_(other.accumulated_transform_),
+        accumulating_transform_(other.accumulating_transform_) {}
 
   enum TransformAccumulation { kFlattenTransform, kAccumulateTransform };
   void Translate(int x, int y, TransformAccumulation);
@@ -73,21 +75,6 @@ class HitTestingTransformState : public RefCounted<HitTestingTransformState> {
   bool accumulating_transform_;
 
  private:
-  HitTestingTransformState(const FloatPoint& p,
-                           const FloatQuad& quad,
-                           const FloatQuad& area)
-      : last_planar_point_(p),
-        last_planar_quad_(quad),
-        last_planar_area_(area),
-        accumulating_transform_(false) {}
-
-  HitTestingTransformState(const HitTestingTransformState& other)
-      : RefCounted<HitTestingTransformState>(),
-        last_planar_point_(other.last_planar_point_),
-        last_planar_quad_(other.last_planar_quad_),
-        last_planar_area_(other.last_planar_area_),
-        accumulated_transform_(other.accumulated_transform_),
-        accumulating_transform_(other.accumulating_transform_) {}
 
   void FlattenWithTransform(const TransformationMatrix&);
 };

third_party/blink/renderer/core/paint/paint_layer.h

@@ -49,6 +49,7 @@
 #include "base/auto_reset.h"
 #include "base/macros.h"
 #include "third_party/blink/renderer/core/core_export.h"
+#include "third_party/blink/renderer/core/layout/hit_testing_transform_state.h"
 #include "third_party/blink/renderer/core/layout/layout_box.h"
 #include "third_party/blink/renderer/core/paint/clip_rects_cache.h"
 #include "third_party/blink/renderer/core/paint/paint_layer_clipper.h"
@@ -1131,14 +1132,14 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
                            HitTestResult&,
                            const HitTestRecursionData& recursion_data,
                            bool applied_transform,
-                           const HitTestingTransformState* = nullptr,
+                           HitTestingTransformState* = nullptr,
                            double* z_offset = nullptr);
   PaintLayer* HitTestLayerByApplyingTransform(
       PaintLayer* root_layer,
       PaintLayer* container_layer,
       HitTestResult&,
       const HitTestRecursionData& recursion_data,
-      const HitTestingTransformState* = nullptr,
+      HitTestingTransformState* = nullptr,
       double* z_offset = nullptr,
       const LayoutPoint& translation_offset = LayoutPoint());
   PaintLayer* HitTestChildren(
@@ -1146,13 +1147,13 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
       PaintLayer* root_layer,
       HitTestResult&,
       const HitTestRecursionData& recursion_data,
-      const HitTestingTransformState*,
+      HitTestingTransformState*,
       double* z_offset_for_descendants,
       double* z_offset,
-      const HitTestingTransformState* unflattened_transform_state,
+      HitTestingTransformState* unflattened_transform_state,
       bool depth_sort_descendants);
 
-  scoped_refptr<HitTestingTransformState> CreateLocalTransformState(
+  HitTestingTransformState CreateLocalTransformState(
       PaintLayer* root_layer,
       PaintLayer* container_layer,
       const HitTestRecursionData& recursion_data,
@@ -1169,14 +1170,13 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
                                    const HitTestLocation&,
                                    HitTestFilter,
                                    bool& inside_clip_rect) const;
-  PaintLayer* HitTestTransformedLayerInFragments(
-      PaintLayer* root_layer,
-      PaintLayer* container_layer,
-      HitTestResult&,
-      const HitTestRecursionData&,
-      const HitTestingTransformState*,
-      double* z_offset,
-      ShouldRespectOverflowClipType);
+  PaintLayer* HitTestTransformedLayerInFragments(PaintLayer* root_layer,
+                                                 PaintLayer* container_layer,
+                                                 HitTestResult&,
+                                                 const HitTestRecursionData&,
+                                                 HitTestingTransformState*,
+                                                 double* z_offset,
+                                                 ShouldRespectOverflowClipType);
   bool HitTestClippedOutByClipPath(PaintLayer* root_layer,
                                    const HitTestLocation&) const;