FIX: Apply Visual Viewport composer height calc in iOS only

FIX: Apply Visual Viewport composer height calc in iOS only

diff --git a/app/assets/javascripts/discourse/components/composer-body.js.es6 b/app/assets/javascripts/discourse/components/composer-body.js.es6
index b1af547..99cf7b6 100644
--- a/app/assets/javascripts/discourse/components/composer-body.js.es6
+++ b/app/assets/javascripts/discourse/components/composer-body.js.es6
@@ -132,12 +132,16 @@ export default Ember.Component.extend(KeyEnterEscape, {
       $document.on(END_EVENTS, endDrag);
     });
 
-    if (window.visualViewport !== undefined) {
+    if (this.shouldUseVisualViewportListener()) {
       this.viewportResize();
       window.visualViewport.addEventListener("resize", this.viewportResize);
     }
   },
 
+  shouldUseVisualViewportListener() {
+    return this.capabilities.isIOS && window.visualViewport !== undefined;
+  },
+
   viewportResize() {
     const composerVH = window.visualViewport.height * 0.01;
 
@@ -174,7 +178,7 @@ export default Ember.Component.extend(KeyEnterEscape, {
   willDestroyElement() {
     this._super(...arguments);
     this.appEvents.off("composer:resize", this, this.resize);
-    if (window.visualViewport !== undefined) {
+    if (this.shouldUseVisualViewportListener()) {
       window.visualViewport.removeEventListener("resize", this.viewportResize);
     }
   },

GitHub sha: ea4e9dba