Change tooltip corner radius to 4px.

theme_draw.cc

Index: theme_draw.cc
diff --git a/theme_draw.cc b/theme_draw.cc
index 96e8a82370bdae7fac94e44ffadb1f25923f1451..dfefe39eae972acdfaa40e418f73ebc030c86fb8 100644
--- a/theme_draw.cc
+++ b/theme_draw.cc
@@ -246,9 +246,9 @@ static const double TOOLTIP_SHADOW_B = 0;
 // Alpha for shadow pixels, from outer-most to inner-most.
 static const double TOOLTIP_SHADOW_ALPHAS[] = { 0.1, 0.2 };
 
-// Outermost shadow corner radius is 10 pixel tooltip border corner radius
+// Outermost shadow corner radius is 4-pixel tooltip border corner radius
 // plus TOOLTIP_SHADOW_DEPTH.
-static const int TOOLTIP_CORNER_RADIUS = 10 + TOOLTIP_SHADOW_DEPTH;
+static const int TOOLTIP_CORNER_RADIUS = 4 + TOOLTIP_SHADOW_DEPTH;
 
 // Widget name of GtkCombBox popup menu.
 static const char* kGtkComboBoxPopupMenu = "gtk-combobox-popup-menu";