Shows Japanese and English mixed queries correctly.

ui/gfx/render_text_linux.cc

Index: ui/gfx/render_text_linux.cc
diff --git a/ui/gfx/render_text_linux.cc b/ui/gfx/render_text_linux.cc
index e6a1ab725e4cda13a895e29a6fd1decb587d60aa..188b6a711125acd824318e7082bc064ccd2ed504 100644
--- a/ui/gfx/render_text_linux.cc
+++ b/ui/gfx/render_text_linux.cc
@@ -83,12 +83,25 @@ Size RenderTextLinux::GetStringSize() {
   EnsureLayout();
   int width = 0, height = 0;
   pango_layout_get_pixel_size(layout_, &width, &height);
-  return Size(width, height);
+  // pango_layout_get_pixel_size() returns the minimal size to render the given

[msw, 2013/07/11 22:47:29]

DCHECK that |height| is smaller, and just return GetFontListHeight().

[Yuki, 2013/07/12 08:25:53]

I'm not sure if it's guaranteed that the pango value is not greater than the
font size.

What happens if...
1. You specified only Latin font. (e.g. Arial)
2. You drew non-Latin characters. (e.g. Japanese "あ")
and, what happens especially if
1-b. You specified 10px Arial
2-b. You don't have 10px (or smaller) Japanese font.  If the minimum size of
Japanese font were 20px, what happens?

I'm afraid that Pango would use 20px Japanese font even though you specified
10px Arial.

I thought there is no guarantee.  You may have only fixed-size font (no scalable
font) and may not be able to draw some text in the specified size.  I thought
the font metrics is just a hint.

I think it's safe to return the max of font height or actual pango value.

[msw, 2013/07/12 09:36:04]

Fair enough; I thought FontLists might track fallback fonts, but I was wrong.

+  // text, and the height can be smaller than the font height.  This means the
+  // baseline may change as the content text changes.  Since we'd like to keep
+  // the same baseline as much as possible, we respect the height determined by
+  // the font list, unless the actual height is higher than the height of the
+  // font list.
+  return Size(width, std::max(height, GetFontListHeight()));
 }
 
 int RenderTextLinux::GetBaseline() {
   EnsureLayout();
-  return PANGO_PIXELS(pango_layout_get_baseline(layout_));
+  // pango_layout_get_baseline() returns the baseline based on the minimal size
+  // to render the given text, and the baseline can be smaller than the font
+  // baseline.  This means the baseline may change as the content text changes.
+  // Since we'd like to keep the same baseline as much as possible, we respect
+  // the baseline determined by the font list, unless the actual baseline is
+  // greater than the baseline of the font list.
+  return std::max(PANGO_PIXELS(pango_layout_get_baseline(layout_)),

[msw, 2013/07/11 22:47:29]

DCHECK that the pango value is smaller, and just return GetFontListBaseline().

[Yuki, 2013/07/12 08:25:53]

Ditto.

+                  GetFontListBaseline());
 }
 
 SelectionModel RenderTextLinux::FindCursorPosition(const Point& point) {
@@ -364,8 +377,7 @@ void RenderTextLinux::DrawVisualText(Canvas* canvas) {
   DCHECK(layout_);
 
   // Skia will draw glyphs with respect to the baseline.
-  Vector2d offset(GetTextOffset() +
-      Vector2d(0, PANGO_PIXELS(pango_layout_get_baseline(layout_))));
+  Vector2d offset(GetTextOffset() + Vector2d(0, GetBaseline()));
 
   SkScalar x = SkIntToScalar(offset.x());
   SkScalar y = SkIntToScalar(offset.y());