Enable Roboto by default for testing purpose.

ui/gfx/render_text_unittest.cc

 // 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.
 
 #include "ui/gfx/render_text.h"
 
 #include <algorithm>
 
 #include "base/format_macros.h"
 #include "base/i18n/break_iterator.h"
@@ skipping 2405 matching lines @@
     render_text->Draw(canvas.get());
     int width = render_text->GetStringSize().width();
     ASSERT_LT(width + kTestWidth, kCanvasSize.width());
     const uint32* buffer = static_cast<const uint32*>(
         surface->peekPixels(NULL, NULL));
     ASSERT_NE(nullptr, buffer);
 
     for (int y = 0; y < kCanvasSize.height(); ++y) {
       // Allow one column of anti-aliased pixels past the expected width.
       SkColor color = buffer[width + y * kCanvasSize.width()];
-      EXPECT_LT(230U, color_utils::GetLuminanceForColor(color)) << string;
+      EXPECT_LT(220U, color_utils::GetLuminanceForColor(color)) << string;
       for (int x = 1; x < kTestWidth; ++x) {
         color = buffer[width + x + y * kCanvasSize.width()];
         EXPECT_EQ(SK_ColorWHITE, color) << string;
       }
     }
   }
 }
 
 // This test validates that the RenderText centering baseline is greater than
 // the font list baseline for a valid display rect.
@@ skipping 22 matching lines @@
             base::StringToLowerASCII(fonts[0].GetActualFontNameForTesting()));
 
   scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
   render_text->SetDisplayRect(Rect(0, 0, 25, 25));
   render_text->SetFontList(font_list);
   EXPECT_GT(render_text->GetBaseline(), font_list.GetBaseline());
 }
 #endif
 
 }  // namespace gfx