ScrollableArea::pixelsPerLine should return viewport pixels in use-zoom-for-dsf mode

third_party/WebKit/Source/web/ChromeClientImpl.cpp

Index: third_party/WebKit/Source/web/ChromeClientImpl.cpp
diff --git a/third_party/WebKit/Source/web/ChromeClientImpl.cpp b/third_party/WebKit/Source/web/ChromeClientImpl.cpp
index 06bcb3706bd9ef17808263ecdf769edbe280f4e7..4da51955f3be50deb361af5ca47ef0a0141f67db 100644
--- a/third_party/WebKit/Source/web/ChromeClientImpl.cpp
+++ b/third_party/WebKit/Source/web/ChromeClientImpl.cpp
@@ -520,12 +520,13 @@ IntRect ChromeClientImpl::viewportToScreen(const IntRect& rectInViewport) const
     return screenRect;
 }
 
-FloatRect ChromeClientImpl::windowToViewport(const FloatRect& rectInWindow) const
+float ChromeClientImpl::windowToViewportScalar(const float scalarValue) const
 {
-    WebFloatRect viewportRect(rectInWindow);
-    if (m_webView->client())
-        m_webView->client()->convertWindowToViewport(&viewportRect);
-    return viewportRect;
+    if (!m_webView->client())
+        return scalarValue;
+    WebFloatRect viewportRect(0, 0, scalarValue, 0);
+    m_webView->client()->convertWindowToViewport(&viewportRect);
+    return viewportRect.width;
 }
 
 WebScreenInfo ChromeClientImpl::screenInfo() const