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

ui/gfx/size_base.h

Index: ui/gfx/size_base.h
diff --git a/ui/gfx/size_base.h b/ui/gfx/size_base.h
index 0ec62e499e2aa9258815d1f6064be90c74d3d2db..3d171f1cce011b9075251d3032465f04b72bd95d 100644
--- a/ui/gfx/size_base.h
+++ b/ui/gfx/size_base.h
@@ -28,8 +28,8 @@ class UI_EXPORT SizeBase {
     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_;
@@ -42,20 +42,11 @@ class UI_EXPORT SizeBase {
   }
 
   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.