Move ‘setAllVisibleHighlights’ method and add a test for it

It makes more sense that this method is implemented in the Sidebar instead of Host

src/annotator/host.coffee

@@ -64,9 +64,3 @@ module.exports = class Host extends Guest
   destroy: ->
     @frame.remove()
     super
-
-  setAllVisibleHighlights: (shouldShowHighlights) ->
-    @crossframe.call('setVisibleHighlights', shouldShowHighlights)
-
-    # Let the Toolbar know about this event
-    this.publish 'setVisibleHighlights', shouldShowHighlights

src/annotator/sidebar.coffee

@@ -190,3 +190,9 @@ module.exports = class Sidebar extends Host
 
   isOpen: ->
     !@frame.hasClass('annotator-collapsed')
+
+  setAllVisibleHighlights: (shouldShowHighlights) ->
+    @crossframe.call('setVisibleHighlights', shouldShowHighlights)
+
+    # Let the Toolbar know about this event
+    this.publish 'setVisibleHighlights', shouldShowHighlights

src/annotator/test/sidebar-test.coffee

@@ -243,3 +243,13 @@ describe 'Sidebar', ->
       sidebar.hide()
 
       assert.isFalse sidebar.visibleHighlights
+
+  describe '#setAllVisibleHighlights', ->
+
+    it 'sets the state through crossframe and emits', ->
+      sidebar = createSidebar({})
+      sandbox.stub(sidebar, 'publish')
+      sidebar.setAllVisibleHighlights(true)
+      assert.calledWith(fakeCrossFrame.call, 'setVisibleHighlights', true)
+      assert.calledWith(sidebar.publish, 'setVisibleHighlights', true)
+