Add utility functions for reference counting.

Bug 26851951

Change-Id: I5494d61927eb4c1faff320aa7cd6cebe81800f29
Reviewed-on: https://swiftshader-review.googlesource.com/4712
Tested-by: Nicolas Capens <capn@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>

src/OpenGL/common/Image.cpp

diff --git a/src/OpenGL/common/Image.cpp b/src/OpenGL/common/Image.cpp
index e4a1c87..73a8656 100644
--- a/src/OpenGL/common/Image.cpp
+++ b/src/OpenGL/common/Image.cpp
@@ -1165,6 +1165,11 @@
 		release();
 	}
 
+	bool Image::isChildOf(const egl::Texture *parent) const
+	{
+		return parentTexture == parent;
+	}
+
 	void Image::loadImageData(GLint xoffset, GLint yoffset, GLint zoffset, GLsizei width, GLsizei height, GLsizei depth, GLenum format, GLenum type, const UnpackInfo& unpackInfo, const void *input)
 	{
 		GLsizei inputPitch = ComputePitch((unpackInfo.rowLength == 0) ? width : unpackInfo.rowLength, format, type, unpackInfo.alignment);