Region::makeBoundsSelf() efficiently turns a region to its bounds

include/ui/Region.h

@@ -51,6 +51,9 @@ public:
     inline  Rect        getBounds() const   { return mBounds; }
     inline  Rect        bounds() const      { return getBounds(); }
 
+            // the region becomes its bounds
+            Region&     makeBoundsSelf();
+    
             void        clear();
             void        set(const Rect& r);
             void        set(uint32_t w, uint32_t h);

libs/ui/Region.cpp

@@ -87,6 +87,12 @@ Region& Region::operator = (const Region& rhs)
     return *this;
 }
 
+Region& Region::makeBoundsSelf()
+{
+    mStorage.clear();
+    return *this;
+}
+
 void Region::clear()
 {
     mBounds.clear();