tests: Add Framework support for reading RT images

DeviceCanDraw - Indicates if device is capable of drawing
for use in tests that require shader execution, etc.

CopyOut - Copies RT image to a staging image.

Read - Returns a 16x16 pixel block.

DeviceIsMockICD -  Indicates if device identifies itself as the
Mock ICD according to its device properties.  Can be fooled by DevSim.
diff --git a/tests/vkrenderframework.h b/tests/vkrenderframework.h
index 38eefda..5b44275 100644
--- a/tests/vkrenderframework.h
+++ b/tests/vkrenderframework.h
@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2015-2017 The Khronos Group Inc.
- * Copyright (c) 2015-2017 Valve Corporation
- * Copyright (c) 2015-2017 LunarG, Inc.
+ * Copyright (c) 2015-2019 The Khronos Group Inc.
+ * Copyright (c) 2015-2019 Valve Corporation
+ * Copyright (c) 2015-2019 LunarG, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -110,6 +110,8 @@
     bool InstanceExtensionEnabled(const char *name);
     bool DeviceExtensionSupported(VkPhysicalDevice dev, const char *layer, const char *name, uint32_t specVersion = 0);
     bool DeviceExtensionEnabled(const char *name);
+    bool DeviceIsMockICD();
+    bool DeviceCanDraw();
 
    protected:
     VkApplicationInfo app_info;
@@ -281,6 +283,10 @@
 
     VkResult CopyImage(VkImageObj &src_image);
 
+    VkResult CopyImageOut(VkImageObj &dst_image);
+
+    std::array<std::array<uint32_t, 16>, 16> Read();
+
     VkImage image() const { return handle(); }
 
     VkImageView targetView(VkFormat format) {