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

ui/gfx/size_base_impl.h

Index: ui/gfx/size_base_impl.h
diff --git a/ui/gfx/size_base_impl.h b/ui/gfx/size_base_impl.h
new file mode 100644
index 0000000000000000000000000000000000000000..9e87468a9b3f13c843ea7c367dbe85257b73dc44
--- /dev/null
+++ b/ui/gfx/size_base_impl.h
@@ -0,0 +1,37 @@
+// 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/gfx/size_base.h"
+
+#include "base/logging.h"
+
+// This file provides the implementation for SizeBase template and
+// used to instantiate the base class for Size and SizeF classes.
+#if !defined(UI_IMPLEMENTATION)
+#error "This file is intended for UI implementation only"
+#endif
+
+namespace gfx {
+
+template<typename Class, typename Type>
+void SizeBase<Class, Type>::set_width(Type width) {
+  DCHECK(!(width < 0));
+  width_ = width < 0 ? 0 : width;
+}
+
+template<typename Class, typename Type>
+void SizeBase<Class, Type>::set_height(Type height) {
+  DCHECK(!(height < 0));
+  height_ = height < 0 ? 0 : height;
+}
+
+template<typename Class, typename Type>
+SizeBase<Class, Type>::SizeBase(Type width, Type height)
+    : width_(width < 0 ? 0 : width),
+      height_(height < 0 ? 0 : height) {
+  DCHECK(!(width < 0));
+  DCHECK(!(height < 0));
+}
+
+}  // namespace gfx