cc: Don't consider HUD layer for touches

cc/math_util.cc

Index: cc/math_util.cc
diff --git a/cc/math_util.cc b/cc/math_util.cc
index f5c0cb4eae3f447f214018ba766bfa102ca7ea9d..47bddd3a4b1ecbe0c4c4ead4cda787c75544f4a1 100644
--- a/cc/math_util.cc
+++ b/cc/math_util.cc
@@ -386,6 +386,26 @@ gfx::Vector2dF MathUtil::projectVector(gfx::Vector2dF source, gfx::Vector2dF des
     return gfx::Vector2dF(projectedLength * destination.x(), projectedLength * destination.y());
 }
 
+bool MathUtil::pointHitsRect(const gfx::PointF& screenSpacePoint,
+                             const gfx::Transform& localSpaceToScreenSpaceTransform,
+                             gfx::RectF localSpaceRect)
+{
+    // If the transform is not invertible, then assume that this point doesn't hit this rect.
+    gfx::Transform inverseLocalSpaceToScreenSpace(gfx::Transform::kSkipInitialization);
+    if (!localSpaceToScreenSpaceTransform.GetInverse(&inverseLocalSpaceToScreenSpace))
+        return false;
+
+    // Transform the hit test point from screen space to the local space of the given rect.
+    bool clipped = false;
+    gfx::PointF hitTestPointInLocalSpace = projectPoint(inverseLocalSpaceToScreenSpace, screenSpacePoint, clipped);
+
+    // If projectPoint could not project to a valid value, then we assume that this point doesn't hit this rect.
+    if (clipped)
+        return false;
+
+    return localSpaceRect.Contains(hitTestPointInLocalSpace);
+}
+
 scoped_ptr<base::Value> MathUtil::asValue(gfx::Size s) {
   scoped_ptr<base::DictionaryValue> res(new base::DictionaryValue());
   res->SetDouble("width", s.width());