Bug 1525304 - Automatically apply "primary" style to buttons with autofocus. r=Gijs

Differential Revision: https://phabricator.services.mozilla.com/D18696

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

browser/base/content/aboutTabCrashed.xhtml

@@ -77,7 +77,7 @@
       <div class="button-container">
         <button id="closeTab" data-l10n-id="crashed-close-tab-button"></button>
         <button id="restoreTab" class="primary" data-l10n-id="crashed-restore-tab-button"></button>
-        <button id="restoreAll" autofocus="true" class="primary" data-l10n-id="crashed-restore-all-button"></button>
+        <button id="restoreAll" autofocus="true" data-l10n-id="crashed-restore-all-button"/>
       </div>
     </div>
   </body>

browser/components/aboutconfig/content/aboutconfig.html

@@ -37,7 +37,7 @@
       </div>
 
       <div class="button-container">
-        <button autofocus class="primary" onclick="onWarningButtonClick();"
+        <button autofocus onclick="onWarningButtonClick();"
                 data-l10n-id="about-config-warning-button"></button>
       </div>
     </div>

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

@@ -255,16 +255,19 @@ xul|menulist[disabled="true"] {
   opacity: 0.4;
 }
 
+html|button[autofocus],
 *|button.primary {
   background-color: var(--in-content-primary-button-background);
   color: var(--in-content-selected-text) !important;
 }
 
+html|button[autofocus]:enabled:hover,
 html|button.primary:enabled:hover,
 xul|button.primary:not([disabled="true"]):hover {
   background-color: var(--in-content-primary-button-background-hover);
 }
 
+html|button[autofocus]:enabled:hover:active,
 html|button.primary:enabled:hover:active,
 xul|button.primary:not([disabled="true"]):hover:active {
   background-color: var(--in-content-primary-button-background-active);