ui: Prefer +/- operators to apply offsets.

ui/gfx/rect_unittest.cc

Index: ui/gfx/rect_unittest.cc
diff --git a/ui/gfx/rect_unittest.cc b/ui/gfx/rect_unittest.cc
index 621e5d90fc73b9d8c844660425a6678897b97bcf..07d79a9e89fe2c9ca728beb2027a0350e1d54de5 100644
--- a/ui/gfx/rect_unittest.cc
+++ b/ui/gfx/rect_unittest.cc
@@ -700,4 +700,25 @@ TEST(RectTest, IsExpressibleAsRect) {
   EXPECT_FALSE(gfx::RectF(0, 0, 1, infinity).IsExpressibleAsRect());
 }
 
+TEST(RectTest, Offset) {
+  Rect i(1, 2, 3, 4);
+
+  EXPECT_EQ(Rect(2, 1, 3, 4).ToString(), (i + Vector2d(1, -1)).ToString());
+  i += Vector2d(1, -1);
+  EXPECT_EQ(Rect(2, 1, 3, 4).ToString(), i.ToString());
+  EXPECT_EQ(Rect(1, 2, 3, 4).ToString(), (i - Vector2d(1, -1)).ToString());
+  i -= Vector2d(1, -1);
+  EXPECT_EQ(Rect(1, 2, 3, 4).ToString(), i.ToString());
+
+  RectF f(1.1f, 2.2f, 3.3f, 4.4f);
+  EXPECT_EQ(RectF(2.2f, 1.1f, 3.3f, 4.4f).ToString(),
+            (f + Vector2dF(1.1f, -1.1f)).ToString());
+  f += Vector2dF(1.1f, -1.1f);
+  EXPECT_EQ(RectF(2.2f, 1.1f, 3.3f, 4.4f).ToString(), f.ToString());
+  EXPECT_EQ(RectF(1.1f, 2.2f, 3.3f, 4.4f).ToString(),
+            (f - Vector2dF(1.1f, -1.1f)).ToString());
+  f -= Vector2dF(1.1f, -1.1f);
+  EXPECT_EQ(RectF(1.1f, 2.2f, 3.3f, 4.4f).ToString(), f.ToString());
+}
+
 }  // namespace gfx