Refactor DrawTextureQuad and CheckPixels in gl_tests util

gpu/command_buffer/tests/gl_test_utils.h

Index: gpu/command_buffer/tests/gl_test_utils.h
diff --git a/gpu/command_buffer/tests/gl_test_utils.h b/gpu/command_buffer/tests/gl_test_utils.h
index d4292248285766b79cac5febb3d9f2cd8572fee6..8b31ac39bfac0782007903dcd7197ca51646994c 100644
--- a/gpu/command_buffer/tests/gl_test_utils.h
+++ b/gpu/command_buffer/tests/gl_test_utils.h
@@ -12,10 +12,6 @@
 
 #include <vector>
 
-namespace gfx {
-class Size;
-}  // namespace gfx
-
 class GLTestHelper {
  public:
   static const uint8_t kCheckClearValue = 123u;
@@ -64,12 +60,16 @@ class GLTestHelper {
                           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_