Refactor DrawTextureQuad and CheckPixels in gl_tests util

gpu/command_buffer/tests/gl_compressed_copy_texture_CHROMIUM_unittest.cc

 // Copyright (c) 2015 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.
 
 #ifndef GL_GLEXT_PROTOTYPES
 #define GL_GLEXT_PROTOTYPES
 #endif
 
 #include <GLES2/gl2.h>
 #include <GLES2/gl2ext.h>
@@ skipping 133 matching lines @@
 
   // Load texture.
   glActiveTexture(GL_TEXTURE0);
   glBindTexture(GL_TEXTURE_2D, textures_[1]);
   glUniform1i(texture_loc, 0);
 
   // Draw.
   glDrawArrays(GL_TRIANGLES, 0, 6);
   glFlush();
 
-  GLTestHelper::CheckPixels(0, 0, 4, 4, 0, kCompressedImageColor);
+  GLTestHelper::CheckPixels(0, 0, 4, 4, 0, kCompressedImageColor, nullptr);
   EXPECT_TRUE(GL_NO_ERROR == glGetError());
 }
 
 TEST_F(GLCompressedCopyTextureCHROMIUMTest, InternalFormat) {
   struct Image {
     const GLint format;
     const uint8_t* data;
     const GLsizei data_size;
 
     Image(const GLint format, const uint8_t* data, const GLsizei data_size)
@@ skipping 233 matching lines @@
   glGetIntegerv(GL_TEXTURE_BINDING_2D, &bound_texture);
   EXPECT_EQ(texture_ids[0], static_cast<GLuint>(bound_texture));
   glBindTexture(GL_TEXTURE_2D, 0);
 
   glDeleteTextures(2, texture_ids);
 
   EXPECT_TRUE(GL_NO_ERROR == glGetError());
 }
 
 }  // namespace gpu