Bug 1496042 - Set a background-color for the statusbar on Windows 7. r=jorgk

mail/themes/windows/mail/addrbook/addressbook.css

@@ -210,12 +210,3 @@ toolbox > toolbar:last-of-type {
     --toolbox-border-bottom-color: #aabccf;
   }
 }
-
-@media (-moz-os-version: windows-win7) and (-moz-windows-default-theme) {
-
-  #status-bar {
-    -moz-appearance: none;
-    border-style: none;
-    border-top: 1px solid ThreeDShadow;
-  }
-}

mail/themes/windows/mail/compose/messengercompose.css

@@ -812,12 +812,6 @@ toolbar:not(:-moz-lwtheme) {
                       hsla(0, 0%, 100%, .1));
     box-shadow: none;
   }
-
-  #status-bar {
-    -moz-appearance: none;
-    border-style: none;
-    border-top: 1px solid threedshadow;
-  }
 }
 
 @media (-moz-os-version: windows-win8) and (-moz-windows-default-theme),

mail/themes/windows/mail/mailWindow1.css

@@ -722,7 +722,6 @@ treechildren::-moz-tree-cell-text(imapdeleted) {
     }
 
     #messengerWindow[sizemode=normal] statusbar {
-      -moz-appearance: none;
       margin-top: -1px;
       border: 1px solid var(--glassShadowColor);
       border-top-color: threedshadow;

mail/themes/windows/mail/messageWindow.css

@@ -58,14 +58,6 @@
   border-bottom: 4px solid highlight;
 }
 
-@media (-moz-windows-compositor) {
-  #status-bar {
-    -moz-appearance: none;
-    border-style: none;
-    border-top: 1px solid ThreeDShadow;
-  }
-}
-
 @media (-moz-os-version: windows-win10) and (-moz-windows-default-theme) {
   #menubar-items > #mail-menubar > menu {
     -moz-appearance: menuitem;

mail/themes/windows/mail/messenger.css

@@ -762,6 +762,16 @@ statusbarpanel label {
   margin-bottom: 0;
 }
 
+@media (-moz-os-version: windows-win7) and (-moz-windows-default-theme),
+       (-moz-os-version: windows-win8) and (-moz-windows-default-theme) {
+  #status-bar:not(:-moz-lwtheme) {
+    -moz-appearance: none;
+    border-style: none;
+    border-top: 1px solid ThreeDShadow;
+    background-color: var(--toolbar-bgcolor);
+  }
+}
+
 @media (-moz-windows-classic) {
   statusbarpanel:not(:-moz-lwtheme) {
     -moz-appearance: statusbarpanel;