Cleanup usage of CSSPropertyID and CSSValueID inside Blink.

Source/core/rendering/RenderThemeChromiumMac.mm

Index: Source/core/rendering/RenderThemeChromiumMac.mm
diff --git a/Source/core/rendering/RenderThemeChromiumMac.mm b/Source/core/rendering/RenderThemeChromiumMac.mm
index 92b53730503d5332831d14f0b0b32fd9bfc08c58..42169be799286a0f354796d5e88be14c9744a38c 100644
--- a/Source/core/rendering/RenderThemeChromiumMac.mm
+++ b/Source/core/rendering/RenderThemeChromiumMac.mm
@@ -253,7 +253,7 @@ static FontWeight toFontWeight(NSInteger appKitFontWeight)
     return fontWeights[appKitFontWeight - 1];
 }
 
-void RenderThemeChromiumMac::systemFont(int cssValueId, FontDescription& fontDescription) const
+void RenderThemeChromiumMac::systemFont(CSSValueID cssValueId, FontDescription& fontDescription) const
 {
     DEFINE_STATIC_LOCAL(FontDescription, systemFont, ());
     DEFINE_STATIC_LOCAL(FontDescription, smallSystemFont, ());
@@ -388,7 +388,7 @@ void RenderThemeChromiumMac::platformColorsDidChange()
     RenderTheme::platformColorsDidChange();
 }
 
-Color RenderThemeChromiumMac::systemColor(int cssValueId) const
+Color RenderThemeChromiumMac::systemColor(CSSValueID cssValueId) const
 {
     {
         HashMap<int, RGBA32>::iterator it = m_systemColorCache.find(cssValueId);
@@ -493,6 +493,8 @@ Color RenderThemeChromiumMac::systemColor(int cssValueId) const
         case CSSValueWindowtext:
             color = convertNSColorToColor([NSColor windowFrameTextColor]);
             break;
+        default:
+            break;
     }
 
     if (!color.isValid())