Add -moz-windows-accent-color-is-dark

#31 point 4

dom/base/nsGkAtomList.h

@@ -2231,6 +2231,7 @@ GK_ATOM(scrollbar_end_forward, "scrollbar-end-forward")
 GK_ATOM(scrollbar_thumb_proportional, "scrollbar-thumb-proportional")
 GK_ATOM(overlay_scrollbars, "overlay-scrollbars")
 GK_ATOM(windows_accent_color_applies, "windows-accent-color-applies")
+GK_ATOM(windows_accent_color_is_dark, "windows-accent-color-is-dark")
 GK_ATOM(windows_default_theme, "windows-default-theme")
 GK_ATOM(mac_graphite_theme, "mac-graphite-theme")
 GK_ATOM(mac_yosemite_theme, "mac-yosemite-theme")
@@ -2261,6 +2262,7 @@ GK_ATOM(_moz_scrollbar_end_forward, "-moz-scrollbar-end-forward")
 GK_ATOM(_moz_scrollbar_thumb_proportional, "-moz-scrollbar-thumb-proportional")
 GK_ATOM(_moz_overlay_scrollbars, "-moz-overlay-scrollbars")
 GK_ATOM(_moz_windows_accent_color_applies, "-moz-windows-accent-color-applies")
+GK_ATOM(_moz_windows_accent_color_is_dark, "-moz-windows-accent-color-is-dark")
 GK_ATOM(_moz_windows_default_theme, "-moz-windows-default-theme")
 GK_ATOM(_moz_mac_graphite_theme, "-moz-mac-graphite-theme")
 GK_ATOM(_moz_mac_yosemite_theme, "-moz-mac-yosemite-theme")

layout/style/nsCSSRuleProcessor.cpp

@@ -1132,6 +1132,11 @@ InitSystemMetrics()
     sSystemMetrics->AppendElement(nsGkAtoms::windows_accent_color_applies);
   }
 
+  rv = LookAndFeel::GetInt(LookAndFeel::eIntID_WindowsAccentColorIsDark, &metricResult);
+  if (NS_SUCCEEDED(rv) && metricResult) {
+    sSystemMetrics->AppendElement(nsGkAtoms::windows_accent_color_is_dark);
+  }
+
   rv = LookAndFeel::GetInt(LookAndFeel::eIntID_DWMCompositor, &metricResult);
   if (NS_SUCCEEDED(rv) && metricResult) {
     sSystemMetrics->AppendElement(nsGkAtoms::windows_compositor);

layout/style/nsMediaFeatures.cpp

@@ -723,6 +723,14 @@ nsMediaFeatures::features[] = {
     { &nsGkAtoms::windows_accent_color_applies },
     GetSystemMetric
   },
+  {
+    &nsGkAtoms::_moz_windows_accent_color_is_dark,
+    nsMediaFeature::eMinMaxNotAllowed,
+    nsMediaFeature::eBoolInteger,
+    nsMediaFeature::eNoRequirements,
+    { &nsGkAtoms::windows_accent_color_is_dark },
+    GetSystemMetric
+  },  
   {
     &nsGkAtoms::_moz_windows_compositor,
     nsMediaFeature::eMinMaxNotAllowed,

widget/LookAndFeel.h

@@ -251,6 +251,15 @@ public:
      */
     eIntID_WindowsAccentColorApplies,
     
+    /*
+     * A Boolean value to determine whether the Windows accent color
+     * is considered dark and should get bright text/controls.
+     *
+     * The value of this metric is not used on other platforms. These platforms
+     * should return NS_ERROR_NOT_IMPLEMENTED when queried for this metric.
+     */
+    eIntID_WindowsAccentColorIsDark,
+
     /*
      * A Boolean value to determine whether the Windows default theme is
      * being used.

widget/windows/nsLookAndFeel.cpp

@@ -442,6 +442,14 @@ nsLookAndFeel::GetIntImpl(IntID aID, int32_t &aResult)
           aResult = NS_SUCCEEDED(GetAccentColor(unused)) ? 1 : 0;
         }
         break;
+    case eIntID_WindowsAccentColorIsDark:
+        {
+          nscolor accentColor;
+          if (NS_SUCCEEDED(GetAccentColor(accentColor))) {
+            aResult = AccentColorIsDark(accentColor) ? 1 : 0;
+          }
+        }
+        break;
     case eIntID_WindowsGlass:
         // Aero Glass is only available prior to Windows 8 when DWM is used.
         aResult = (nsUXThemeData::CheckForCompositor() && !IsWin8OrLater());

widget/windows/nsWindow.cpp

@@ -7138,6 +7138,11 @@ nsWindow::OnSysColorChanged()
     // so all presentations get notified properly.
     // See nsWindow::GlobalMsgWindowProc.
     NotifySysColorChanged();
+    // On Windows 10 only, we trigger a theme change to pick up changed media
+    // queries that are needed for accent color changes.
+    if (IsWin10OrLater()) {
+      NotifyThemeChanged();
+    }
   }
 }