Move SkGLContext and some GrGLInterface implementations to skgputest module

include/gpu/gl/GrGLInterface.h

Index: include/gpu/gl/GrGLInterface.h
diff --git a/include/gpu/gl/GrGLInterface.h b/include/gpu/gl/GrGLInterface.h
index cbf9b1a59fc9917c003aa89bd137d9463cf4b0a4..4ba516617f3eb76f82d3ef1cef7f00c37531a991 100644
--- a/include/gpu/gl/GrGLInterface.h
+++ b/include/gpu/gl/GrGLInterface.h
@@ -43,39 +43,18 @@ const GrGLInterface* GrGLDefaultInterface();
  */
 SK_API const GrGLInterface* GrGLCreateNativeInterface();
 
-#if SK_MESA
-/**
- * Creates a GrGLInterface for an OSMesa context.
- */
-SK_API const GrGLInterface* GrGLCreateMesaInterface();
-#endif
-
-#if SK_ANGLE
-/**
- * Creates a GrGLInterface for an ANGLE context.
- */
-SK_API const GrGLInterface* GrGLCreateANGLEInterface();
-#endif
-
-#if SK_COMMAND_BUFFER
-/**
- * Creates a GrGLInterface for a Command Buffer context.
- */
-SK_API const GrGLInterface* GrGLCreateCommandBufferInterface();
+#if GR_GL_PER_GL_FUNC_CALLBACK
+typedef void (*GrGLInterfaceCallbackProc)(const GrGLInterface*);
+typedef intptr_t GrGLInterfaceCallbackData;
 #endif
 
 /**
  * Creates a null GrGLInterface that doesn't draw anything. Used for measuring
- * CPU overhead.
+ * CPU overhead. TODO: We would like to move this to tools/gpu/gl/null but currently
+ * Chromium is using it in its unit tests.
  */
 const SK_API GrGLInterface* GrGLCreateNullInterface();
 
-/**
- * Creates a debugging GrGLInterface that doesn't draw anything. Used for
- * finding memory leaks and invalid memory accesses.
- */
-const GrGLInterface* GrGLCreateDebugInterface();
-
 /** Function that returns a new interface identical to "interface" but without support for
     GL_NV_path_rendering. */
 const GrGLInterface* GrGLInterfaceRemoveNVPR(const GrGLInterface*);