[Effen] remove some redundant styles

Some of the styles we have aren't really needed, so remove them to make it clearer what we weed to actually support to keep the stocks app running.

R=eseidel@chromium.org

Review URL: https://codereview.chromium.org/1128173007

framework/components/button.dart

@@ -8,11 +8,7 @@ import 'material.dart';
 
 class Button extends Component {
   static final Style _style = new Style('''
-    display: inline-flex;
-    transform: translateX(0);
     -webkit-user-select: none;
-    justify-content: center;
-    align-items: center;
     height: 36px;
     min-width: 64px;
     padding: 0 8px;

framework/components/checkbox.dart

@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import '../fn.dart';
+import '../layout.dart';
 import 'button_base.dart';
 import 'dart:sky' as sky;
 
@@ -11,8 +12,6 @@ typedef void ValueChanged(value);
 class Checkbox extends ButtonBase {
   static final Style _style = new Style('''
     transform: translateX(0);
-    display: flex;
-    flex-direction: row;
     justify-content: center;
     align-items: center;
     -webkit-user-select: none;
@@ -68,8 +67,9 @@ class Checkbox extends ButtonBase {
 
   UINode buildContent() {
     return new EventListenerNode(
-      new Container(
+      new FlexContainer(
         style: _style,
+        direction: FlexDirection.Row,
         children: [
           new Container(
             style: highlight ? _containerHighlightStyle : _containerStyle,

framework/components/floating_action_button.dart

@@ -11,17 +11,13 @@ class FloatingActionButton extends Component {
   // TODO(abarth): We need a better way to become a container for absolutely
   // positioned elements.
   static final Style _style = new Style('''
-    transform: translateX(0);
     width: 56px;
     height: 56px;
     background-color: ${Red[500]};
     border-radius: 28px;'''
   );
   static final Style _clipStyle = new Style('''
-    transform: translateX(0);
     position: absolute;
-    display: flex;
-    flex-direction: row;
     justify-content: center;
     align-items: center;
     top: 0;

framework/components/menu_item.dart

@@ -9,18 +9,12 @@ import 'ink_well.dart';
 
 class MenuItem extends ButtonBase {
   static final Style _style = new Style('''
-    transform: translateX(0);
-    display: flex;
-    flex-direction: row;
     align-items: center;
     height: 48px;
     -webkit-user-select: none;'''
   );
 
   static final Style _highlightStyle = new Style('''
-    transform: translateX(0);
-    display: flex;
-    flex-direction: row;
     align-items: center;
     height: 48px;
     background: rgba(153, 153, 153, 0.4);