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

ui/gfx/size_unittest.cc

Index: ui/gfx/size_unittest.cc
diff --git a/ui/gfx/size_unittest.cc b/ui/gfx/size_unittest.cc
index d647f4c0957b6acb50bf75cd83fdae342ab76315..5523b755370280956f45b9f8a3dcef41f2be0681 100644
--- a/ui/gfx/size_unittest.cc
+++ b/ui/gfx/size_unittest.cc
@@ -91,4 +91,16 @@ TEST(SizeTest, ToRoundedSize) {
   EXPECT_EQ(Size(-11, -11), ToRoundedSize(SizeF(-10.9999f, -10.9999f)));
 }
 
+TEST(SizeTest, ClampToZero) {
+  EXPECT_EQ(Size().ToString(), Size(-1, -1).ToString());
+  EXPECT_EQ(Size().ToString(), Size(0, -1).ToString());
+  EXPECT_EQ(Size().ToString(), Size(-1, 0).ToString());
+
+  EXPECT_EQ(SizeF().ToString(), SizeF(-1, -1).ToString());
+  EXPECT_EQ(SizeF().ToString(), SizeF(0, -1).ToString());
+  EXPECT_EQ(SizeF().ToString(), SizeF(-1, 0).ToString());
+
+  EXPECT_EQ(SizeF().ToString(), SizeF(1, 1).Scale(-1).ToString());
+}
+
 }  // namespace gfx