Revert 167062 - ui: Remove gfx::Size::ClampToNonNegative, prevent negative sizes always.

ui/gfx/size_base.h

Index: ui/gfx/size_base.h
===================================================================
--- ui/gfx/size_base.h	(revision 167065)
+++ ui/gfx/size_base.h	(working copy)
@@ -32,8 +32,8 @@
     set_height(height_ + height);
   }
 
-  void set_width(Type width);
-  void set_height(Type height);
+  void set_width(Type width) { width_ = width; }
+  void set_height(Type height) { height_ = height; }
 
   void ClampToMax(const Class& max) {
     width_ = width_ <= max.width_ ? width_ : max.width_;
@@ -46,11 +46,20 @@
   }
 
   bool IsEmpty() const {
-    return (width_ == 0) || (height_ == 0);
+    return (width_ <= 0) || (height_ <= 0);
   }
 
+  void ClampToNonNegative() {
+    if (width_ < 0)
+      width_ = 0;
+    if (height_ < 0)
+      height_ = 0;
+  }
+
  protected:
-  SizeBase(Type width, Type height);
+  SizeBase(Type width, Type height)
+      : width_(width),
+        height_(height) {}
 
   // Destructor is intentionally made non virtual and protected.
   // Do not make this public.