Add detection for rotation and flip overlay transforms

cc/base/math_util.cc

 // 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/base/math_util.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 
 #include "base/trace_event/trace_event_argument.h"
 #include "base/values.h"
 #include "ui/gfx/geometry/quad_f.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/rect_conversions.h"
 #include "ui/gfx/geometry/rect_f.h"
 #include "ui/gfx/geometry/vector2d_f.h"
+#include "ui/gfx/geometry/vector3d_f.h"
 #include "ui/gfx/transform.h"
 
 namespace cc {
 
 const double MathUtil::kPiDouble = 3.14159265358979323846;
 const float MathUtil::kPiFloat = 3.14159265358979323846f;
 
 static HomogeneousCoordinate ProjectHomogeneousPoint(
     const gfx::Transform& transform,
     const gfx::PointF& p) {
@@ skipping 832 matching lines @@
 }
 
 double MathUtil::AsDoubleSafely(double value) {
   return std::min(value, std::numeric_limits<double>::max());
 }
 
 float MathUtil::AsFloatSafely(float value) {
   return std::min(value, std::numeric_limits<float>::max());
 }
 
+gfx::Vector3dF MathUtil::GetXAxis(const gfx::Transform& transform) {
+  return gfx::Vector3dF(transform.matrix().getFloat(0, 0),
+                        transform.matrix().getFloat(1, 0),
+                        transform.matrix().getFloat(2, 0));
+}
+
+gfx::Vector3dF MathUtil::GetYAxis(const gfx::Transform& transform) {
+  return gfx::Vector3dF(transform.matrix().getFloat(0, 1),
+                        transform.matrix().getFloat(1, 1),
+                        transform.matrix().getFloat(2, 1));
+}
+
 }  // namespace cc