IVGCVSW-2102: Fix Pooling2D CpuRef indexing bug

* Fixes bug when calcuating indexes for NHWC in
  Pooling2D CpuRef implementation, it now uses
  TensorBufferArrayView.
* Adds 2-Channel unit tests for Pooling2d on CpuRef,
  Cl and Neon. The single channel tests were not
  properly exercising Pooling2d using NHWC data layout.
* Refactors Pooling2D NHWC tests so that the input and
  output data are permuted to NHWC when necessary,
  instead of hard coding the data in NHWC format.

Change-Id: I5b9d41ed425ff283ea8c8ef6b1266ae0bc80f43b
diff --git a/src/backends/test/LayerTests.hpp b/src/backends/test/LayerTests.hpp
index 0e45024..392d3bf 100644
--- a/src/backends/test/LayerTests.hpp
+++ b/src/backends/test/LayerTests.hpp
@@ -99,10 +99,16 @@
 LayerTestResult<float,   4> IgnorePaddingMaxPooling2dSize3Test(armnn::IWorkloadFactory& workloadFactory);
 LayerTestResult<uint8_t, 4> IgnorePaddingMaxPooling2dSize3Uint8Test(armnn::IWorkloadFactory& workloadFactory);
 
-LayerTestResult<float,   4> SimpleAveragePooling2dTest(armnn::IWorkloadFactory& workloadFactory);
-LayerTestResult<float,   4> SimpleAveragePooling2dNhwcTest(armnn::IWorkloadFactory& workloadFactory);
-LayerTestResult<uint8_t, 4> SimpleAveragePooling2dUint8Test(armnn::IWorkloadFactory& workloadFactory);
-LayerTestResult<uint8_t, 4> SimpleAveragePooling2dUint8NhwcTest(armnn::IWorkloadFactory& workloadFactory);
+LayerTestResult<float,   4> SimpleMaxPooling2dTest(armnn::IWorkloadFactory& workloadFactory,
+                                                   const armnn::DataLayoutIndexed& dataLayout);
+LayerTestResult<uint8_t, 4> SimpleMaxPooling2dUint8Test(armnn::IWorkloadFactory& workloadFactory,
+                                                        const armnn::DataLayoutIndexed& dataLayout);
+
+LayerTestResult<float,   4> SimpleAveragePooling2dTest(armnn::IWorkloadFactory& workloadFactory,
+                                                       const armnn::DataLayoutIndexed& dataLayout);
+LayerTestResult<uint8_t, 4> SimpleAveragePooling2dUint8Test(armnn::IWorkloadFactory& workloadFactory,
+                                                            const armnn::DataLayoutIndexed& dataLayout);
+
 LayerTestResult<float,   4> IgnorePaddingAveragePooling2dSize3x2Stride2x2Test(armnn::IWorkloadFactory& workloadFactory,
                                                                               bool forceNoPadding);
 LayerTestResult<float,   4> IgnorePaddingSimpleAveragePooling2dTest(armnn::IWorkloadFactory& workloadFactory);
@@ -113,8 +119,10 @@
 LayerTestResult<float,   4> IgnorePaddingAveragePooling2dSize3Test(armnn::IWorkloadFactory& workloadFactory);
 LayerTestResult<uint8_t, 4> IgnorePaddingAveragePooling2dSize3Uint8Test(armnn::IWorkloadFactory& workloadFactory);
 
-LayerTestResult<float,   4> SimpleL2Pooling2dTest(armnn::IWorkloadFactory& workloadFactory);
-LayerTestResult<uint8_t, 4> SimpleL2Pooling2dUint8Test(armnn::IWorkloadFactory& workloadFactory);
+LayerTestResult<float,   4> SimpleL2Pooling2dTest(armnn::IWorkloadFactory& workloadFactory,
+                                                  const armnn::DataLayoutIndexed& dataLayout);
+LayerTestResult<uint8_t, 4> SimpleL2Pooling2dUint8Test(armnn::IWorkloadFactory& workloadFactory,
+                                                       const armnn::DataLayoutIndexed& dataLayout);
 
 LayerTestResult<float,   4> L2Pooling2dSize3Stride1Test(armnn::IWorkloadFactory& workloadFactory);
 LayerTestResult<uint8_t, 4> L2Pooling2dSize3Stride1Uint8Test(armnn::IWorkloadFactory& workloadFactory);