[gtk] make tab title font irrespective of display DPI.

The font size is changed from 9 to 13 in order to offset the new correction. The font has the same same pixel size that was displayed before on my 101 DPI display.

BUG=62536
TEST=using Xephyr -dpi XXX

Review URL: http://codereview.chromium.org/4837002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@65971 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 10 insertions, 8 deletions

diff --git a/chrome/browser/gtk/tabs/tab_renderer_gtk.cc b/chrome/browser/gtk/tabs/tab_renderer_gtk.cc
index 318fcbe..cf1f62c0 100644
--- a/chrome/browser/gtk/tabs/tab_renderer_gtk.cc
+++ b/chrome/browser/gtk/tabs/tab_renderer_gtk.cc
@@ -22,6 +22,7 @@
 #include "chrome/common/notification_service.h"
 #include "gfx/canvas_skia_paint.h"
 #include "gfx/favicon_size.h"
+#include "gfx/platform_font_gtk.h"
 #include "gfx/skbitmap_operations.h"
 #include "grit/app_resources.h"
 #include "grit/generated_resources.h"
@@ -1070,10 +1071,11 @@ void TabRendererGtk::InitResources() {
   LoadTabImages();
 
   ResourceBundle& rb = ResourceBundle::GetSharedInstance();
-  // Force the font size to 9pt, which matches Windows' default font size
-  // (taken from the system).
   const gfx::Font& base_font = rb.GetFont(ResourceBundle::BaseFont);
-  title_font_ = new gfx::Font(base_font.GetFontName(), 9);
+  // Dividing by the pango scale factor maintains an absolute pixel size across
+  // all DPIs.
+  int size = static_cast<int>(13 / gfx::PlatformFontGtk::GetPangoScaleFactor());
+  title_font_ = new gfx::Font(base_font.GetFontName(), size);
   title_font_height_ = title_font_->GetHeight();
 
   crashed_fav_icon = rb.GetBitmapNamed(IDR_SAD_FAVICON);
diff --git a/gfx/platform_font_gtk.cc b/gfx/platform_font_gtk.cc
index 5ed7793..7633c10 100644
--- a/gfx/platform_font_gtk.cc
+++ b/gfx/platform_font_gtk.cc
@@ -135,7 +135,7 @@ PlatformFontGtk::PlatformFontGtk(NativeFont native_font) {
     // font_size_ is treated as scaled (see comment in GetPangoScaleFactor). If
     // we get here the font size is absolute though, and we need to invert the
     // scale so that when scaled in the rest of this class everything lines up.
-    size /= PlatformFontGtk::GetPangoScaleFactor();
+    size /= GetPangoScaleFactor();
   }
 
   // Find best match font for |family_name| to make sure we can get
@@ -350,7 +350,7 @@ void PlatformFontGtk::PaintSetup(SkPaint* paint) const {
   paint->setAntiAlias(false);
   paint->setSubpixelText(false);
   paint->setTextSize(
-      SkFloatToScalar(font_size_ * PlatformFontGtk::GetPangoScaleFactor()));
+      SkFloatToScalar(font_size_ * GetPangoScaleFactor()));
   paint->setTypeface(typeface_);
   paint->setFakeBoldText((gfx::Font::BOLD & style_) && !typeface_->isBold());
   paint->setTextSkewX((gfx::Font::ITALIC & style_) && !typeface_->isItalic() ?
diff --git a/gfx/platform_font_gtk.h b/gfx/platform_font_gtk.h
index bd26d8f..bc7be66 100644
--- a/gfx/platform_font_gtk.h
+++ b/gfx/platform_font_gtk.h
@@ -46,6 +46,9 @@ class PlatformFontGtk : public PlatformFont {
   virtual int GetFontSize() const;
   virtual NativeFont GetNativeFont() const;
 
+  // Return the scale factor for fonts that account for DPI.
+  static float GetPangoScaleFactor();
+
  private:
   // Create a new instance of this object with the specified properties. Called
   // from DeriveFont.
@@ -72,9 +75,6 @@ class PlatformFontGtk : public PlatformFont {
   // Make |this| a copy of |other|.
   void CopyFont(const Font& other);
 
-  // Return the scale factor for fonts that account for DPI.
-  static float GetPangoScaleFactor();
-
   // The average width of a character, initialized and cached if needed.
   double GetAverageWidth() const;