Stabilize empty rect handling in EnclosingRect.

ui/gfx/geometry/size_f.h

Index: ui/gfx/geometry/size_f.h
diff --git a/ui/gfx/geometry/size_f.h b/ui/gfx/geometry/size_f.h
index 9d1bb5d7e3ed6c18d4ff3d3193a510ae85c70c48..1009ac47df61420c6ebd298bf0c016d153bfc241 100644
--- a/ui/gfx/geometry/size_f.h
+++ b/ui/gfx/geometry/size_f.h
@@ -14,12 +14,15 @@
 
 namespace gfx {
 
+static constexpr float kTrivial = 8.f * std::numeric_limits<float>::epsilon();
+
 // A floating version of gfx::Size.
 class GFX_EXPORT SizeF {
  public:
   constexpr SizeF() : width_(0.f), height_(0.f) {}
   constexpr SizeF(float width, float height)
-      : width_(width >= 0 ? width : 0), height_(height >= 0 ? height : 0) {}
+      : width_(width >= kTrivial ? width : 0.f),
+        height_(height >= kTrivial ? height : 0.f) {}
 
   constexpr explicit SizeF(const Size& size)
       : SizeF(static_cast<float>(size.width()),
@@ -28,8 +31,8 @@ class GFX_EXPORT SizeF {
   constexpr float width() const { return width_; }
   constexpr float height() const { return height_; }
 
-  void set_width(float width) { width_ = fmaxf(0, width); }
-  void set_height(float height) { height_ = fmaxf(0, height); }
+  void set_width(float width) { width_ = width >= kTrivial ? width : 0.f; }
+  void set_height(float height) { height_ = height >= kTrivial ? height : 0.f; }
 
   float GetArea() const;
 
@@ -43,7 +46,9 @@ class GFX_EXPORT SizeF {
   void SetToMin(const SizeF& other);
   void SetToMax(const SizeF& other);
 
-  bool IsEmpty() const { return !width() || !height(); }
+  bool HasHeight() const { return height() > kTrivial; }
+  bool HasWidth() const { return width() > kTrivial; }
+  bool IsEmpty() const { return !HasHeight() || !HasWidth(); }
 
   void Scale(float scale) {
     Scale(scale, scale);