Split StyleSurroundData::padding into four individual Lengths.

third_party/WebKit/Source/platform/Theme.cpp

Index: third_party/WebKit/Source/platform/Theme.cpp
diff --git a/third_party/WebKit/Source/platform/Theme.cpp b/third_party/WebKit/Source/platform/Theme.cpp
index 78cf648f21972bd7b52436bee28a81ff537a2401..ebf8c5ea5450d63a2332cb9f9a74d0332ff91f3a 100644
--- a/third_party/WebKit/Source/platform/Theme.cpp
+++ b/third_party/WebKit/Source/platform/Theme.cpp
@@ -45,7 +45,10 @@ LengthBox Theme::ControlBorder(ControlPart part,
 
 LengthBox Theme::ControlPadding(ControlPart part,
                                 const FontDescription&,
-                                const LengthBox& zoomed_box,
+                                const Length& zoomed_box_top,
+                                const Length& zoomed_box_right,
+                                const Length& zoomed_box_bottom,
+                                const Length& zoomed_box_left,
                                 float) const {
   switch (part) {
     case kMenulistPart:
@@ -54,7 +57,8 @@ LengthBox Theme::ControlPadding(ControlPart part,
     case kRadioPart:
       return LengthBox(0);
     default:
-      return zoomed_box;
+      return LengthBox(zoomed_box_top, zoomed_box_right, zoomed_box_bottom,

[shend, 2017/04/20 07:07:20]

Does this get called often? If so, there might be a cost of copy and
constructing the LengthBox.

[nainar, 2017/04/20 07:13:09]

Yes, it gets called up through StyleResolver::StyleForElement()

[shend, 2017/04/20 07:20:56]

That's annoying. Maybe ask alancutter@ for advice on how to prevent the cost of
constructing a LengthBox?

[nainar, 2017/04/21 00:15:19]

Adding him for owners and asking his opinion on the matter. 

[alancutter (OOO until 2018), 2017/04/21 03:13:32]

It was doing a copy anyway, I wouldn't worry about it.

+                       zoomed_box_left);
   }
 }