support zz command

src/background/index.js

@@ -45,6 +45,9 @@ const doBackgroundAction = (sender, action) => {
   case actions.ZOOM_OUT:
     zooms.zoomOut();
     break;
+  case actions.ZOOM_NEUTRAL:
+    zooms.neutral();
+    break;
   }
 }
 

src/background/key-queue.js

@@ -15,6 +15,7 @@ const DEFAULT_KEYMAP = [
   { keys: [{ code: KeyboardEvent.DOM_VK_L }], action: [ actions.TABS_NEXT, 1 ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_Z }, { code: KeyboardEvent.DOM_VK_I }], action: [ actions.ZOOM_IN ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_Z }, { code: KeyboardEvent.DOM_VK_O }], action: [ actions.ZOOM_OUT ]},
+  { keys: [{ code: KeyboardEvent.DOM_VK_Z }, { code: KeyboardEvent.DOM_VK_Z }], action: [ actions.ZOOM_NEUTRAL]},
   { keys: [{ code: KeyboardEvent.DOM_VK_F }], action: [ actions.FOLLOW_START, false ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_F, shift: true }], action: [ actions.FOLLOW_START, true ]},
   { keys: [{ code: KeyboardEvent.DOM_VK_H, shift: true }], action: [ actions.HISTORY_PREV ]},

src/background/zooms.js

@@ -18,7 +18,7 @@ const zoomIn = (tabId = undefined) => {
       }
     }
   });
-}
+};
 
 const zoomOut = (tabId = undefined) => {
   browser.tabs.getZoom(tabId).then((factor) => {
@@ -29,6 +29,10 @@ const zoomOut = (tabId = undefined) => {
       }
     }
   });
-}
+};
 
-export { zoomIn, zoomOut };
+const neutral = (tabId = undefined) => {
+  browser.tabs.setZoom(tabId, 1);
+};
+
+export { zoomIn, zoomOut, neutral };

src/shared/actions.js

@@ -13,6 +13,7 @@ export const HISTORY_PREV = 'history.prev';
 export const HISTORY_NEXT = 'history.next';
 export const ZOOM_IN = 'zoom.in';
 export const ZOOM_OUT = 'zoom.out';
+export const ZOOM_NEUTRAL = 'zoom.neutral';
 
 const BACKGROUND_ACTION_SET = new Set([
   TABS_CLOSE,
@@ -20,7 +21,8 @@ const BACKGROUND_ACTION_SET = new Set([
   TABS_PREV,
   TABS_NEXT,
   ZOOM_IN,
-  ZOOM_OUT
+  ZOOM_OUT,
+  ZOOM_NEUTRAL
 ]);
 
 const CONTENT_ACTION_SET = new Set([