Get all font unittests running with DirectWrite on Windows 7+

ui/gfx/platform_font_win.cc

Index: ui/gfx/platform_font_win.cc
diff --git a/ui/gfx/platform_font_win.cc b/ui/gfx/platform_font_win.cc
index 5e9d2537e5a188d88bf8b1bd186c36b50376a954..e0612bf3e7a3fd2c475a78e042d653c5ee63e200 100644
--- a/ui/gfx/platform_font_win.cc
+++ b/ui/gfx/platform_font_win.cc
@@ -230,14 +230,19 @@ Font PlatformFontWin::DeriveFontWithHeight(int height, int style) {
     }
     return font;
   }
-
-  LOGFONT font_info;
-  GetObject(GetNativeFont(), sizeof(LOGFONT), &font_info);
-  font_info.lfHeight = height;
-  SetLogFontStyle(style, &font_info);
-
-  HFONT hfont = CreateFontIndirect(&font_info);
-  return DeriveWithCorrectedSize(hfont);
+  // We derive a font with a size delta of 0 initially, i.e the derived font

[msw, 2015/01/12 21:30:55]

Is this necessary given the early return at lines 214/215?

[msw, 2015/01/12 21:30:55]

nit: add a blank line above.

[ananta, 2015/01/12 22:14:15]

Done.

[ananta, 2015/01/12 22:14:15]

The function has changed. 

[ananta, 2015/01/12 22:14:15]

Removed the comment. The function has changed a bit.

+  // starts off with the height of the current font instance.
+  // This is to ensure that we honor the contract of this function which is
+  // to return a font with with height less than or equal to the desired
+  // height.
+  Font font = DeriveFont(0, style);
+  while (font.GetHeight() < height) {
+    Font derived_font = font.Derive(1, style);

[msw, 2015/01/12 21:30:55]

I'm curious about the performance impact here, but I'm not aware of related
perftests. Perhaps an initial CreateFontIndirect would avoid 90% of the
DeriveFont iterations for both loops. Maybe Alexei or Dan have some thoughts?

[ananta, 2015/01/12 22:14:15]

Done. Removed the starting 2 lines which check for whether the current font is
of the desired height. This is as per our discussion that we want to iterate and
return the next available font with the desired height.

+    if (derived_font.GetHeight() > height)
+      break;
+    font = derived_font;
+  }
+  return font;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -518,8 +523,7 @@ PlatformFontWin::HFontRef* PlatformFontWin::CreateHFontRefFromSkia(
   // The calculations below are similar to those in the CreateHFontRef
   // function. The height, baseline and cap height are rounded up to ensure
   // that they match up closely with GDI.
-  const int height = std::ceil(
-      skia_metrics.fDescent - skia_metrics.fAscent + skia_metrics.fLeading);
+  const int height = std::ceil(skia_metrics.fDescent - skia_metrics.fAscent);
   const int baseline = std::max<int>(1, std::ceil(-skia_metrics.fAscent));
   const int cap_height = std::ceil(paint.getTextSize() *
       static_cast<double>(dwrite_font_metrics.capHeight) /