math correctly (#20368)

packages/flutter/lib/src/material/user_accounts_drawer_header.dart

@@ -31,17 +31,17 @@ class _AccountPictures extends StatelessWidget {
           end: 0.0,
           child: new Row(
             children: (otherAccountsPictures ?? <Widget>[]).take(3).map((Widget picture) {
-              return new Container(
-                margin: const EdgeInsetsDirectional.only(start: 8.0),
-                width: 48.0,
-                height: 48.0,
+              return new Padding(
+                padding: const EdgeInsetsDirectional.only(start: 8.0),
                 child: new Semantics(
                   container: true,
-                  child: new Padding(
+                  child: new Container(
+                  padding: const EdgeInsets.only(left: 8.0, bottom: 8.0),
+                    width: 48.0,
+                    height: 48.0,
                     child: picture,
-                    padding: const EdgeInsets.all(4.0),
-                  ),
                  ),
+                )
               );
             }).toList(),
           ),

packages/flutter/test/material/user_accounts_drawer_header_test.dart

@@ -98,8 +98,8 @@ void main() {
 
     expect(avatarATopLeft.dx - topLeft.dx, equals(16.0 + 10.0)); // left padding
     expect(avatarATopLeft.dy - topLeft.dy, equals(16.0 + 20.0)); // add top padding
-    expect(topRight.dx - avatarDTopRight.dx, equals(16.0 + 34.0)); // right padding
-    expect(avatarDTopRight.dy - topRight.dy, equals(16.0 + 24.0)); // add top padding
+    expect(topRight.dx - avatarDTopRight.dx, equals(16.0 + 30.0)); // right padding
+    expect(avatarDTopRight.dy - topRight.dy, equals(16.0 + 20.0)); // add top padding
     expect(avatarDTopRight.dx - avatarCTopRight.dx, equals(40.0 + 16.0)); // size + space between
   });