Remove unnecessary translateZ(0) when doing scale() (#5473)

app/javascript/mastodon/features/compose/components/upload.js

@@ -68,7 +68,7 @@ export default class Upload extends ImmutablePureComponent {
       <div className='compose-form__upload' onMouseEnter={this.handleMouseEnter} onMouseLeave={this.handleMouseLeave}>
         <Motion defaultStyle={{ scale: 0.8 }} style={{ scale: spring(1, { stiffness: 180, damping: 12 }) }}>
           {({ scale }) => (
-            <div className='compose-form__upload-thumbnail' style={{ transform: `translateZ(0) scale(${scale})`, backgroundImage: `url(${media.get('preview_url')})` }}>
+            <div className='compose-form__upload-thumbnail' style={{ transform: `scale(${scale})`, backgroundImage: `url(${media.get('preview_url')})` }}>
               <IconButton icon='times' title={intl.formatMessage(messages.undo)} size={36} onClick={this.handleUndoClick} />
 
               <div className={classNames('compose-form__upload-description', { active })}>

app/javascript/mastodon/features/compose/containers/sensitive_button_container.js

@@ -47,7 +47,7 @@ class SensitiveButton extends React.PureComponent {
             'compose-form__sensitive-button--visible': visible,
           });
           return (
-            <div className={className} style={{ transform: `translateZ(0) scale(${scale})` }}>
+            <div className={className} style={{ transform: `scale(${scale})` }}>
               <IconButton
                 className='compose-form__sensitive-button__icon'
                 title={intl.formatMessage(messages.title)}

app/javascript/mastodon/features/ui/components/upload_area.js

@@ -40,7 +40,7 @@ export default class UploadArea extends React.PureComponent {
         {({ backgroundOpacity, backgroundScale }) =>
           <div className='upload-area' style={{ visibility: active ? 'visible' : 'hidden', opacity: backgroundOpacity }}>
             <div className='upload-area__drop'>
-              <div className='upload-area__background' style={{ transform: `translateZ(0) scale(${backgroundScale})` }} />
+              <div className='upload-area__background' style={{ transform: `scale(${backgroundScale})` }} />
               <div className='upload-area__content'><FormattedMessage id='upload_area.title' defaultMessage='Drag & drop to upload' /></div>
             </div>
           </div>

app/javascript/styles/mastodon/components.scss

@@ -3008,21 +3008,21 @@ button.icon-button.active i.fa-retweet {
   }
 
   .fa-search {
-    transform: translateZ(0) rotate(90deg);
+    transform: rotate(90deg);
 
     &.active {
       pointer-events: none;
-      transform: translateZ(0) rotate(0deg);
+      transform: rotate(0deg);
     }
   }
 
   .fa-times-circle {
     top: 11px;
-    transform: translateZ(0) rotate(0deg);
+    transform: rotate(0deg);
     cursor: pointer;
 
     &.active {
-      transform: translateZ(0) rotate(90deg);
+      transform: rotate(90deg);
     }
 
     &:hover {