Partial revert of https://codereview.chromium.org/1911973002/

content/child/webthemeengine_impl_default.h

Index: content/child/webthemeengine_impl_default.h
diff --git a/content/child/webthemeengine_impl_default.h b/content/child/webthemeengine_impl_default.h
index e4e1c7eaddc2f167e028aeab3ecfdbde5c65c4f9..9de946ecffb3a6183b1c8c116597704cdf4c8a05 100644
--- a/content/child/webthemeengine_impl_default.h
+++ b/content/child/webthemeengine_impl_default.h
@@ -27,6 +27,13 @@ class WebThemeEngineImpl : public blink::WebThemeEngine {
                                     blink::WebThemeEngine::State endState,
                                     double progress,
                                     const blink::WebRect& rect);
+#if defined(OS_WIN)
+  // Caches the scrollbar metrics.

[Evan Stade, 2016/08/29 20:40:35]

is it explained somewhere why this is necessary? Your CL description is very
helpful but it doesn't seem obvious from looking at the code why there's this
extra windows hoopla.

[scottmg, 2016/08/29 20:45:29]

Expanded on the comment here.

+  static void cacheScrollBarMetrics(int32_t vertical_scroll_bar_width,
+                                    int32_t horizontal_scroll_bar_height,
+                                    int32_t vertical_arrow_bitmap_height,
+                                    int32_t horizontal_arrow_bitmap_width);
+#endif
 };
 
 }  // namespace content