Chromium build fix

Adding a getPlane() function in order to not have the "plane" private
member unused, which causes a warning and makes compilation fail.

Change-Id: I3ec08d3439c7e8f3d4314f3b4864d12e9c34d6f4
Reviewed-on: https://swiftshader-review.googlesource.com/18468
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/OpenGL/common/Image.cpp b/src/OpenGL/common/Image.cpp
index 9c2645d..6f38322 100644
--- a/src/OpenGL/common/Image.cpp
+++ b/src/OpenGL/common/Image.cpp
@@ -1225,6 +1225,11 @@
 		return format;
 	}
 
+	size_t ClientBuffer::getPlane() const
+	{
+		return plane;
+	}
+
 	int ClientBuffer::pitchP() const
 	{
 #if defined(__APPLE__)
diff --git a/src/OpenGL/common/Image.hpp b/src/OpenGL/common/Image.hpp
index 5e924c0..5c8175a 100644
--- a/src/OpenGL/common/Image.hpp
+++ b/src/OpenGL/common/Image.hpp
@@ -73,6 +73,7 @@
 	int getWidth() const;
 	int getHeight() const;
 	sw::Format getFormat() const;
+	size_t getPlane() const;
 	int pitchP() const;
 	void retain();
 	void release();