Refactor DrawTextureQuad and CheckPixels in gl_tests util

gpu/command_buffer/tests/gl_pointcoord_unittest.cc

Index: gpu/command_buffer/tests/gl_pointcoord_unittest.cc
diff --git a/gpu/command_buffer/tests/gl_pointcoord_unittest.cc b/gpu/command_buffer/tests/gl_pointcoord_unittest.cc
index 1828aff965d6776d44398e84651b0261c7356a76..d0a0163facce933d8c4f50196f236fe5478c81f2 100644
--- a/gpu/command_buffer/tests/gl_pointcoord_unittest.cc
+++ b/gpu/command_buffer/tests/gl_pointcoord_unittest.cc
@@ -138,7 +138,7 @@ TEST_F(PointCoordTest, MAYBE_RenderTo) {
               static_cast<uint8_t>(s * 255),
               static_cast<uint8_t>((1 - t) * 255), 0, 255,
           };
-          GLTestHelper::CheckPixels(xf, yf, 1, 1, 4, color);
+          GLTestHelper::CheckPixels(xf, yf, 1, 1, 4, color, nullptr);
         }
       }
     }