COMPMID-1995: Minor code fixes.

-Remove FIXMEs and link to tickets.
-Pass large object by const reference.
-Implement copy assignment operator for Window.

Change-Id: I975223ac42ec424f153569a8c963f29e6b86ad29
Signed-off-by: Georgios Pinitas <georgios.pinitas@arm.com>
Reviewed-on: https://review.mlplatform.org/c/899
Comments-Addressed: Arm Jenkins <bsgcomp@arm.com>
Tested-by: Arm Jenkins <bsgcomp@arm.com>
Reviewed-by: Michele Di Giorgio <michele.digiorgio@arm.com>
diff --git a/arm_compute/core/Window.h b/arm_compute/core/Window.h
index 73c8d43..a562279 100644
--- a/arm_compute/core/Window.h
+++ b/arm_compute/core/Window.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2018 ARM Limited.
+ * Copyright (c) 2016-2019 ARM Limited.
  *
  * SPDX-License-Identifier: MIT
  *
@@ -56,6 +56,13 @@
      * @param[in] src Copy the values from src to a new object
      */
     Window(const Window &src);
+    /** Copy assignment operator
+     *
+     * @param[in] rhs Copy the values from rhs to the current object
+     *
+     * @return Reference to the updated object
+     */
+    Window &operator=(const Window &rhs);
 
     /** Describe one of the image's dimensions with a start, end and step.
      *
@@ -384,6 +391,12 @@
     {
         return broadcast_if_dimension_le_one(info.tensor_shape());
     }
+    /** Friend function that swaps the contents of two windows
+     *
+     * @param[in] lhs First window to swap.
+     * @param[in] rhs Second window to swap.
+     */
+    friend void swap(Window &lhs, Window &rhs);
 
 private:
     /** First slice of the window
@@ -407,6 +420,6 @@
 private:
     std::array<Dimension, Coordinates::num_max_dimensions> _dims;
 };
-}
+} // namespace arm_compute
 #include "Window.inl"
 #endif /*__ARM_COMPUTE_WINDOW_H__ */