Enable subpixel positioning for UI

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 2355 matching lines @@
 
   render_text.SetFontList(font_list);
   // Korean character "han".
   render_text.SetText(WideToUTF16(L"\xd55c"));
   render_text.EnsureLayout();
   ASSERT_EQ(1U, render_text.runs_.size());
   EXPECT_EQ(0U, render_text.runs_[0]->CountMissingGlyphs());
 }
 #endif  // defined(OS_WIN)
 
+// Ensure that the width reported by RenderText is sufficient for drawing. Draws
+// to a canvas and checks whether any pixel beyond the width is colored.
+TEST_F(RenderTextTest, TextDoesntClip) {
+  const wchar_t* kTestStrings[] = { L"Save", L"Remove", L"TEST", L"W", L"WWW" };
+
+  skia::RefPtr<SkCanvas> sk_canvas =
+      skia::AdoptRef(SkCanvas::NewRasterN32(300, 50));
+  scoped_ptr<Canvas> canvas(
+      Canvas::CreateCanvasWithoutScaling(sk_canvas.get(), 1.0f));
+  scoped_ptr<RenderText> render_text(RenderText::CreateInstance());
+  render_text->SetDisplayRect(Rect(300, 50));
+  render_text->SetHorizontalAlignment(gfx::ALIGN_LEFT);
+  render_text->SetColor(SK_ColorBLACK);
+
+  for (size_t i = 0; i < arraysize(kTestStrings); ++i) {
+    sk_canvas->clear(SK_ColorWHITE);
+    render_text->SetText(WideToUTF16(kTestStrings[i]));
+    render_text->SetStyle(BOLD, true);
+    render_text->Draw(canvas.get());
+    int width = render_text->GetStringSize().width();
+    ASSERT_LT(width, 300);
+    const uint32* buffer = static_cast<const uint32*>(
+        sk_canvas->peekPixels(NULL, NULL));
+    ASSERT_NE(nullptr, buffer);
+    for (int y = 0; y < 50; ++y) {
+      EXPECT_EQ(SK_ColorWHITE, buffer[width + y * 300])
+          << "String: " << kTestStrings[i];
+    }
+  }
+}
+
 }  // namespace gfx