Make bigger string size in RenderTextHarfBuzz.

ui/gfx/render_text_unittest.cc

Index: ui/gfx/render_text_unittest.cc
diff --git a/ui/gfx/render_text_unittest.cc b/ui/gfx/render_text_unittest.cc
index 542939ea3081369af9a50fdf080f3490eaa7d3d8..1e610cf9d6c4059a7fc8bcbf8492a3c5b578fbdc 100644
--- a/ui/gfx/render_text_unittest.cc
+++ b/ui/gfx/render_text_unittest.cc
@@ -1375,7 +1375,11 @@ TEST_F(RenderTextTest, StringSizeEmptyString) {
   EXPECT_EQ(font_list.GetBaseline(), render_text->GetBaseline());
 
   render_text->SetText(UTF8ToUTF16(" "));
-  EXPECT_EQ(font_list.GetHeight(), render_text->GetStringSize().height());
+  // If the text is not empty, |render_text|'s height could be slightly bigger

[msw, 2015/02/26 00:47:21]

nit:   // |render_text| may be taller than the font to accommodate some glyphs.

+  // than the font height because the font height is calculated for the distance
+  // between the ascent and descent while |render_text| height is computed from
+  // the top and the bottom.
+  EXPECT_LE(font_list.GetHeight(), render_text->GetStringSize().height());
   EXPECT_EQ(font_list.GetBaseline(), render_text->GetBaseline());
 }
 #endif  // !defined(OS_MACOSX)
@@ -1415,7 +1419,10 @@ TEST_F(RenderTextTest, StringSizeRespectsFontListMetrics) {
   render_text->SetFontList(FontList(smaller_font));
   render_text->SetDisplayRect(Rect(0, 0, 0,
                                    render_text->font_list().GetHeight()));
-  EXPECT_EQ(smaller_font.GetHeight(), render_text->GetStringSize().height());
+  // |render_text| height may not be exactly same to |smaller_font|'s height

[msw, 2015/02/26 00:47:21]

nit:   // |render_text| may be taller than the font to accommodate some glyphs.

+  // considering the gap between the top and the ascent.
+  // See http://crbug.com/459812
+  EXPECT_LE(smaller_font.GetHeight(), render_text->GetStringSize().height());
   EXPECT_EQ(smaller_font.GetBaseline(), render_text->GetBaseline());
 
   // Layout the same text with mixed fonts.  The text should be rendered with
@@ -1430,7 +1437,8 @@ TEST_F(RenderTextTest, StringSizeRespectsFontListMetrics) {
                                    render_text->font_list().GetHeight()));
   EXPECT_LT(smaller_font.GetHeight(), render_text->GetStringSize().height());
   EXPECT_LT(smaller_font.GetBaseline(), render_text->GetBaseline());
-  EXPECT_EQ(font_list.GetHeight(), render_text->GetStringSize().height());
+  // Again, it could be slightly different from font's height, see above.

[msw, 2015/02/26 00:47:21]

nit:  // |render_text| may be taller than the font to accommodate some glyphs.

+  EXPECT_LE(font_list.GetHeight(), render_text->GetStringSize().height());
   EXPECT_EQ(font_list.GetBaseline(), render_text->GetBaseline());
 }
 
@@ -1447,7 +1455,7 @@ TEST_F(RenderTextTest, MinLineHeight) {
 
   render_text->SetMinLineHeight(default_size.height() * 2);
   SizeF taller_size = render_text->GetStringSizeF();
-  EXPECT_EQ(default_size.height() * 2, taller_size.height());
+  EXPECT_LT(default_size.height(), taller_size.height());
   EXPECT_EQ(default_size.width(), taller_size.width());
 }