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

content/child/webthemeengine_impl_default.cc

Index: content/child/webthemeengine_impl_default.cc
diff --git a/content/child/webthemeengine_impl_default.cc b/content/child/webthemeengine_impl_default.cc
index 3cbc96027f92082ba66c7953330e541f095c5884..7fa4ba7d6497c2d374257db255e91d283d2c24cc 100644
--- a/content/child/webthemeengine_impl_default.cc
+++ b/content/child/webthemeengine_impl_default.cc
@@ -16,6 +16,23 @@ using blink::WebRect;
 using blink::WebThemeEngine;
 
 namespace content {
+namespace {
+
+#if defined(OS_WIN)
+// The width of a vertical scroll bar in dips.
+int32_t g_vertical_scroll_bar_width;
+
+// The height of a horizontal scroll bar in dips.
+int32_t g_horizontal_scroll_bar_height;
+
+// The height of the arrow bitmap on a vertical scroll bar in dips.
+int32_t g_vertical_arrow_bitmap_height;
+
+// The width of the arrow bitmap on a horizontal scroll bar in dips.
+int32_t g_horizontal_arrow_bitmap_width;
+#endif
+
+}  // namespace
 
 static ui::NativeTheme::Part NativeThemePart(
     WebThemeEngine::Part part) {
@@ -167,8 +184,27 @@ static void GetNativeThemeExtraParams(
 
 blink::WebSize WebThemeEngineImpl::getSize(WebThemeEngine::Part part) {
   ui::NativeTheme::ExtraParams extra;
+  ui::NativeTheme::Part native_theme_part = NativeThemePart(part);
+#if defined(OS_WIN)
+  switch (native_theme_part) {
+    case ui::NativeTheme::kScrollbarDownArrow:
+    case ui::NativeTheme::kScrollbarLeftArrow:
+    case ui::NativeTheme::kScrollbarRightArrow:
+    case ui::NativeTheme::kScrollbarUpArrow:
+    case ui::NativeTheme::kScrollbarHorizontalThumb:
+    case ui::NativeTheme::kScrollbarVerticalThumb:
+    case ui::NativeTheme::kScrollbarHorizontalTrack:
+    case ui::NativeTheme::kScrollbarVerticalTrack: {
+      return gfx::Size(g_vertical_scroll_bar_width,
+                       g_vertical_scroll_bar_width);
+    }
+
+    default:
+      break;
+  }
+#endif
   return ui::NativeTheme::GetInstanceForWeb()->GetPartSize(
-      NativeThemePart(part), ui::NativeTheme::kNormal, extra);
+      native_theme_part, ui::NativeTheme::kNormal, extra);
 }
 
 void WebThemeEngineImpl::paint(
@@ -196,4 +232,18 @@ void WebThemeEngineImpl::paintStateTransition(blink::WebCanvas* canvas,
       NativeThemeState(endState), progress, gfx::Rect(rect));
 }
 
+#if defined(OS_WIN)
+// static
+void WebThemeEngineImpl::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) {
+  g_vertical_scroll_bar_width = vertical_scroll_bar_width;
+  g_horizontal_scroll_bar_height = horizontal_scroll_bar_height;
+  g_vertical_arrow_bitmap_height = vertical_arrow_bitmap_height;
+  g_horizontal_arrow_bitmap_width = horizontal_arrow_bitmap_width;
+}
+#endif
+
 }  // namespace content