A number of paint optimizations to improve overall paint times.

ui/views/controls/textfield/textfield.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/views/controls/textfield/textfield.h"
 
 #include <string>
 
 #include "base/command_line.h"
 #include "base/strings/string_util.h"
@@ skipping 272 matching lines @@
 
 const gfx::Font& Textfield::GetPrimaryFont() const {
   return font_list_.GetPrimaryFont();
 }
 
 void Textfield::SetFont(const gfx::Font& font) {
   SetFontList(gfx::FontList(font));
 }
 
 void Textfield::SetHorizontalMargins(int left, int right) {
+  if (horizontal_margins_were_set_ &&
+      left == margins_.left() && right == margins_.right()) {
+    return;
+  }
   margins_.Set(margins_.top(), left, margins_.bottom(), right);
   horizontal_margins_were_set_ = true;
   if (native_wrapper_)
     native_wrapper_->UpdateHorizontalMargins();
   PreferredSizeChanged();
 }
 
 void Textfield::SetVerticalMargins(int top, int bottom) {
+  if (vertical_margins_were_set_ &&
+      top == margins_.top() && bottom == margins_.bottom()) {
+    return;
+  }
   margins_.Set(top, margins_.left(), bottom, margins_.right());
   vertical_margins_were_set_ = true;
   if (native_wrapper_)
     native_wrapper_->UpdateVerticalMargins();
   PreferredSizeChanged();
 }
 
 void Textfield::RemoveBorder() {
   if (!draw_border_)
     return;
@@ skipping 272 matching lines @@
 NativeTextfieldWrapper* NativeTextfieldWrapper::CreateWrapper(
     Textfield* field) {
 #if defined(OS_WIN) && !defined(USE_AURA)
   if (!Textfield::IsViewsTextfieldEnabled())
     return new NativeTextfieldWin(field);
 #endif
   return new NativeTextfieldViews(field);
 }
 
 }  // namespace views