Do not convert from RectF to Rect by flooring.

ui/gfx/rect.h

Index: ui/gfx/rect.h
diff --git a/ui/gfx/rect.h b/ui/gfx/rect.h
index 652c019ea6abdfa9351096efef9fd7225d61d701..34c82b03e795b779aa689359a45a4f084f689059 100644
--- a/ui/gfx/rect.h
+++ b/ui/gfx/rect.h
@@ -16,6 +16,7 @@
 
 #include "ui/gfx/point.h"
 #include "ui/gfx/rect_base.h"
+#include "ui/gfx/rect_f.h"
 #include "ui/gfx/size.h"
 
 #if defined(OS_WIN)
@@ -67,6 +68,24 @@ class UI_EXPORT Rect : public RectBase<Rect, Point, Size, Insets, int> {
   CGRect ToCGRect() const;
 #endif
 
+  RectF ToRectF() const WARN_UNUSED_RESULT {
+    return RectF(origin().x(), origin().y(), size().width(), size().height());
+  }
+
+  // This fuction is retained to maintain the old behavior, but should never be
+  // used. Every instance of ScaleUnsafe should be replaced with a Scale
+  // followed by ToEnclosingRect or ToEnclosedRect as appropriate.
+  Rect ScaleUnsafe(float scale) const WARN_UNUSED_RESULT;

[sky, 2012/09/27 17:48:30]

Why do we need these? Can't we pick one and make Scale use it? This is
especially confusing when you've updated BackingStoreAura to use the Unsafe one.

+  Rect ScaleUnsafe(float x_scale, float y_scale) const WARN_UNUSED_RESULT;
+
+  RectF Scale(float scale) const WARN_UNUSED_RESULT {
+    return Scale(scale, scale);
+  }
+
+  RectF Scale(float x_scale, float y_scale) const WARN_UNUSED_RESULT {
+    return ToRectF().Scale(x_scale, y_scale);
+  }
+
   std::string ToString() const;
 };