Refactor DrawTextureQuad and CheckPixels in gl_tests util

gpu/command_buffer/tests/gl_iosurface_readback_workaround_unittest.cc

 // Copyright 2016 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 49 matching lines @@
   glGenFramebuffers(1, &framebuffer);
   glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);
   glFramebufferTexture2D(
       GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, source_target, source_texture, 0);
   EXPECT_EQ(static_cast<GLenum>(GL_FRAMEBUFFER_COMPLETE),
             glCheckFramebufferStatus(GL_FRAMEBUFFER));
 
   glClearColor(33.0 / 255.0, 44.0 / 255.0, 55.0 / 255.0, 66.0 / 255.0);
   glClear(GL_COLOR_BUFFER_BIT);
   const uint8_t expected[4] = {33, 44, 55, 66};
-  EXPECT_TRUE(
-      GLTestHelper::CheckPixels(0, 0, 1, 1, 1 /* tolerance */, expected));
+  EXPECT_TRUE(GLTestHelper::CheckPixels(0, 0, 1, 1, 1 /* tolerance */, expected,
+                                        nullptr));
 
   glClearColor(14.0 / 255.0, 15.0 / 255.0, 16.0 / 255.0, 17.0 / 255.0);
   glClear(GL_COLOR_BUFFER_BIT);
   const uint8_t expected2[4] = {14, 15, 16, 17};
-  EXPECT_TRUE(
-      GLTestHelper::CheckPixels(0, 0, 1, 1, 1 /* tolerance */, expected2));
+  EXPECT_TRUE(GLTestHelper::CheckPixels(0, 0, 1, 1, 1 /* tolerance */,
+                                        expected2, nullptr));
 
   glReleaseTexImage2DCHROMIUM(source_target, image_id);
   glDestroyImageCHROMIUM(image_id);
   glDeleteTextures(1, &source_texture);
   glDeleteFramebuffers(1, &framebuffer);
 }
 
 #endif  // defined(OS_MACOSX)
 
 }  // namespace gpu