Just set borders once when creating a views::LabelButton

chrome/test/base/view_event_test_base.h

 // 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.
 
 #ifndef CHROME_TEST_BASE_VIEW_EVENT_TEST_BASE_H_
 #define CHROME_TEST_BASE_VIEW_EVENT_TEST_BASE_H_
 
 // We only want to use ViewEventTestBase in test targets which properly
 // isolate each test case by running each test in a separate process.
 // This way if a test hangs the test launcher can reliably terminate it.
@@ skipping 67 matching lines @@
   void Done();
 
   static void SetUpTestCase();
 
   // Creates a window.
   void SetUp() override;
 
   // Destroys the window.
   void TearDown() override;
 
+  // Returns an empty Size. Subclasses that want a preferred size other than
+  // that of the View returned by CreateContentsView should override this
+  // appropriately.
+  virtual gfx::Size GetPreferredSize() const;
+
   // Overridden from views::WidgetDelegate:
   bool CanResize() const override;
   views::View* GetContentsView() override;
   const views::Widget* GetWidget() const override;
   views::Widget* GetWidget() override;
 
   // Overridden to do nothing so that this class can be used in runnable tasks.
   void AddRef() {}
   void Release() {}
 
  protected:
   ~ViewEventTestBase() override;
 
   // Returns the view that is added to the window.
   virtual views::View* CreateContentsView() = 0;
 
   // Called once the message loop is running.
   virtual void DoTestOnMessageLoop() = 0;
 
   // Invoke from test main. Shows the window, starts the message loop and
   // schedules a task that invokes DoTestOnMessageLoop.
   void StartMessageLoopAndRunTest();
 
-  // Returns an empty Size. Subclasses that want a preferred size other than
-  // that of the View returned by CreateContentsView should override this
-  // appropriately.
-  virtual gfx::Size GetPreferredSize() const;
-
   // Creates a task that calls the specified method back. The specified
   // method is called in such a way that if there are any test failures
   // Done is invoked.
   template <class T, class Method>
   base::Closure CreateEventTask(T* target, Method method) {
     return base::Bind(&ViewEventTestBase::RunTestMethod, this,
                       base::Bind(method, target));
   }
 
   // Spawns a new thread posts a MouseMove in the background.
@@ skipping 33 matching lines @@
 // Convenience macro for defining a ViewEventTestBase. See class description
 // of ViewEventTestBase for details.
 #define VIEW_TEST(test_class, name) \
   TEST_F(test_class, name) {\
     StartMessageLoopAndRunTest();\
   }
 
 #endif  // defined(HAS_OUT_OF_PROC_TEST_RUNNER)
 
 #endif  // CHROME_TEST_BASE_VIEW_EVENT_TEST_BASE_H_