Make various gfx classes more amenable to use as compile-time constants.

ui/gfx/geometry/insets.cc

 // Copyright (c) 2009 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/gfx/geometry/insets.h"
 
 #include "base/strings/stringprintf.h"
 
 namespace gfx {
 
-Insets::Insets() : Insets(0) {}
-
-Insets::Insets(int all) : Insets(all, all, all, all) {}
-
-Insets::Insets(int vertical, int horizontal)
-    : Insets(vertical, horizontal, vertical, horizontal) {}
-
-Insets::Insets(int top, int left, int bottom, int right)
-    : top_(top), left_(left), bottom_(bottom), right_(right) {}
-
-Insets::~Insets() {}
-
 std::string Insets::ToString() const {
   // Print members in the same order of the constructor parameters.
   return base::StringPrintf("%d,%d,%d,%d", top(),  left(), bottom(), right());
 }
 
 }  // namespace gfx