Scale scrollbar width in popup properly

third_party/WebKit/Source/web/WebPagePopupImpl.cpp

Index: third_party/WebKit/Source/web/WebPagePopupImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebPagePopupImpl.cpp b/third_party/WebKit/Source/web/WebPagePopupImpl.cpp
index f75540807ab011d538b0ffb69988dac7f5bdf0c1..d4eacc7f32b983831c1c58e44fc32441ff6ca661 100644
--- a/third_party/WebKit/Source/web/WebPagePopupImpl.cpp
+++ b/third_party/WebKit/Source/web/WebPagePopupImpl.cpp
@@ -55,6 +55,7 @@
 #include "platform/tracing/TraceEvent.h"
 #include "public/platform/WebCompositeAndReadbackAsyncCallback.h"
 #include "public/platform/WebCursorInfo.h"
+#include "public/platform/WebFloatRect.h"
 #include "public/web/WebAXObject.h"
 #include "public/web/WebFrameClient.h"
 #include "public/web/WebViewClient.h"
@@ -96,6 +97,12 @@ class PagePopupChromeClient final : public EmptyChromeClient {
     return rectInScreen;
   }
 
+  float windowToViewportScalar(const float scalarValue) const override {
+    WebFloatRect viewportRect(0, 0, scalarValue, 0);
+    m_popup->widgetClient()->convertWindowToViewport(&viewportRect);
+    return viewportRect.width;
+  }
+
   void addMessageToConsole(LocalFrame*,
                            MessageSource,
                            MessageLevel,