Add detection for rotation and flip overlay transforms

Rotations and flips were listed in the enum, but not being allowed by
OverlayCandidate::GetOverlayTransform.

BUG=

Review URL: https://codereview.chromium.org/1135813005

Cr-Commit-Position: refs/heads/master@{#329719}

2 files changed, 20 insertions, 0 deletions

diff --git a/cc/base/math_util.cc b/cc/base/math_util.cc
index e2fd565..969e52a 100644
--- a/cc/base/math_util.cc
+++ b/cc/base/math_util.cc
@@ -15,6 +15,7 @@
 #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 {
@@ -867,4 +868,16 @@ 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
diff --git a/cc/base/math_util.h b/cc/base/math_util.h
index 56fdd17..749b9bd 100644
--- a/cc/base/math_util.h
+++ b/cc/base/math_util.h
@@ -33,6 +33,7 @@ class RectF;
 class Transform;
 class Vector2dF;
 class Vector2d;
+class Vector3dF;
 }
 
 namespace cc {
@@ -240,6 +241,12 @@ class CC_EXPORT MathUtil {
   // If the value is inf, returns max double/float representation.
   static double AsDoubleSafely(double value);
   static float AsFloatSafely(float value);
+
+  // Returns vector that x axis (1,0,0) transforms to under given transform.
+  static gfx::Vector3dF GetXAxis(const gfx::Transform& transform);
+
+  // Returns vector that y axis (0,1,0) transforms to under given transform.
+  static gfx::Vector3dF GetYAxis(const gfx::Transform& transform);
 };
 
 }  // namespace cc