Fix focus ring damage sometimes being 1 pixel off.

third_party/WebKit/Source/core/style/StyleBackgroundData.h

Index: third_party/WebKit/Source/core/style/StyleBackgroundData.h
diff --git a/third_party/WebKit/Source/core/style/StyleBackgroundData.h b/third_party/WebKit/Source/core/style/StyleBackgroundData.h
index 18e7069b3ffa038192d2e3410d848a41a26e46f6..1512616438ddf021942537a1a69b4983770f460e 100644
--- a/third_party/WebKit/Source/core/style/StyleBackgroundData.h
+++ b/third_party/WebKit/Source/core/style/StyleBackgroundData.h
@@ -36,7 +36,7 @@ namespace blink {
 // TODO(sashab): Move this into a private class on ComputedStyle, and remove
 // all methods on it, merging them into copy/creation methods on ComputedStyle
 // instead. Keep the allocation logic, only allocating a new object if needed.
-class StyleBackgroundData : public RefCounted<StyleBackgroundData> {
+class CORE_EXPORT StyleBackgroundData : public RefCounted<StyleBackgroundData> {
  public:
   static PassRefPtr<StyleBackgroundData> create() {
     return adoptRef(new StyleBackgroundData);