Bug 1506212 - Fix more in-content button colors. r=bgrins

Differential Revision: https://phabricator.services.mozilla.com/D11555

--HG--
extra : moz-landing-system : lando

browser/themes/shared/aboutSessionRestore.css

@@ -26,7 +26,7 @@ body[dir="rtl"] #tabsToggle:after {
 
 #tabsToggle {
   cursor: pointer;
-  color: #0a84ff;
+  color: #0a84ff !important;
   -moz-context-properties: fill;
   fill: currentColor;
   border: none;

toolkit/themes/shared/in-content/common.inc.css

@@ -217,7 +217,7 @@ xul|menulist[disabled="true"] {
 *|button.primary {
   background-color: var(--in-content-primary-button-background);
   border-color: transparent;
-  color: var(--in-content-selected-text);
+  color: var(--in-content-selected-text) !important;
 }
 
 html|button.primary:enabled:hover,