Clear button for date/time inputs should be zoomable on Mac

We will stop using NSCancelButtonCell and draw it using GraphicsContext.
This will also enable zooming for search field cancel buttons.

The change to RenderThemeChromiumMac::controlSizeForSystemFont fixes a bug where all controls were drawn with NSRegularControlSize when zoomed. Because we fixed this we had to introduce different padding depending on the control size (searchFieldHorizontalPaddings).

BUG=247572

Review URL: https://chromiumcodereview.appspot.com/16532002

git-svn-id: svn://svn.chromium.org/blink/trunk@152845 bbb929c8-8fbe-4397-9dbb-9b2b20218538
diff --git a/Source/core/css/html.css b/Source/core/css/html.css
index 5b97e32..057d693 100644
--- a/Source/core/css/html.css
+++ b/Source/core/css/html.css
@@ -447,8 +447,7 @@
     display: block;
     -webkit-flex: none;
     -webkit-user-modify: read-only !important;
-    -webkit-align-self: flex-start;
-    margin: auto 0;
+    -webkit-margin-start: 1px;
 }
 
 input[type="search"]::-webkit-search-decoration {