Refactor DrawTextureQuad and CheckPixels in gl_tests util

gpu/command_buffer/tests/gl_test_utils.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Helper functions for GL.
 
 #ifndef GPU_COMMAND_BUFFER_TESTS_GL_TEST_UTILS_H_
 #define GPU_COMMAND_BUFFER_TESTS_GL_TEST_UTILS_H_
 
 #include <GLES2/gl2.h>
 #include <stdint.h>
 
 #include <vector>
 
-namespace gfx {
-class Size;
-}  // namespace gfx
-
 class GLTestHelper {
  public:
   static const uint8_t kCheckClearValue = 123u;
 
   static bool HasExtension(const char* extension);
   static bool CheckGLError(const char* msg, int line);
 
   // Compiles a shader.
   // Does not check for errors, always returns shader.
   static GLuint CompileShader(GLenum type, const char* shaderSrc);
@@ skipping 28 matching lines @@
   // Returns the created buffer.
   static GLuint SetupColorsForUnitQuad(
       GLint location, const GLfloat color[4], GLenum usage);
 
   // Checks an area of pixels for a color.
   static bool CheckPixels(GLint x,
                           GLint y,
                           GLsizei width,
                           GLsizei height,
                           GLint tolerance,
-                          const uint8_t* color);
+                          const uint8_t* color,
+                          const uint8_t* mask);

[Zhenyao Mo, 2017/01/03 23:09:00]

Can you add a comment what "mask" means?

Say, "if mark is nullptr, compare all color channels; otherwise, compare the
channels whose corresponding mask bit is true"

[qiankun, 2017/01/04 02:39:57]

Done.

 
   // Uses ReadPixels to save an area of the current FBO/Backbuffer.
   static bool SaveBackbufferAsBMP(const char* filename, int width, int height);
 
-  static void DrawTextureQuad(GLenum target, const gfx::Size& size);
+  static void DrawTextureQuad(const char* vertex_src,
+                              const char* fragment_src,
+                              const char* position_name,
+                              const char* sampler_name);
 };
 
 #endif  // GPU_COMMAND_BUFFER_TESTS_GL_TEST_UTILS_H_