ui: Remove gfx::Size::ClampToNonNegative, prevent negative sizes always.

ui/gfx/size_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 UI_GFX_SIZE_BASE_H_
 #define UI_GFX_SIZE_BASE_H_
 
 #include "ui/base/ui_export.h"
 
 namespace gfx {
@@ skipping 10 matching lines @@
   void SetSize(Type width, Type height) {
     set_width(width);
     set_height(height);
   }
 
   void Enlarge(Type width, Type height) {
     set_width(width_ + width);
     set_height(height_ + height);
   }
 
-  void set_width(Type width) { width_ = width; }
-  void set_height(Type height) { height_ = height; }
+  void set_width(Type width);
+  void set_height(Type height);
 
   void ClampToMax(const Class& max) {
     width_ = width_ <= max.width_ ? width_ : max.width_;
     height_ = height_ <= max.height_ ? height_ : max.height_;
   }
 
   void ClampToMin(const Class& min) {
     width_ = width_ >= min.width_ ? width_ : min.width_;
     height_ = height_ >= min.height_ ? height_ : min.height_;
   }
 
   bool IsEmpty() const {
-    return (width_ <= 0) || (height_ <= 0);
-  }
-
-  void ClampToNonNegative() {
-    if (width_ < 0)
-      width_ = 0;
-    if (height_ < 0)
-      height_ = 0;
+    return (width_ == 0) || (height_ == 0);
   }
 
  protected:
-  SizeBase(Type width, Type height)
-      : width_(width),
-        height_(height) {}
+  SizeBase(Type width, Type height);
 
   // Destructor is intentionally made non virtual and protected.
   // Do not make this public.
   ~SizeBase() {}
 
  private:
   Type width_;
   Type height_;
 };
 
 }  // namespace gfx
 
 #endif  // UI_GFX_SIZE_BASE_H_