Replace hide-scrollbars flag with a web setting.

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
index f3710f0d20314c96e033feab385d84e7201682cc..6d015c29b0a3eaf90876db5e5937bd045f49b0b4 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -1051,6 +1051,9 @@ void PaintLayerScrollableArea::setHasHorizontalScrollbar(bool hasScrollbar)
     if (FreezeScrollbarsScope::scrollbarsAreFrozen())
         return;
 
+    if (box().frame()->settings() && box().frame()->settings()->hideScrollbars())
+        hasScrollbar = false;
+
     if (hasScrollbar == hasHorizontalScrollbar())
         return;
 
@@ -1078,6 +1081,9 @@ void PaintLayerScrollableArea::setHasVerticalScrollbar(bool hasScrollbar)
     if (FreezeScrollbarsScope::scrollbarsAreFrozen())
         return;
 
+    if (box().frame()->settings() && box().frame()->settings()->hideScrollbars())
+        hasScrollbar = false;
+
     if (hasScrollbar == hasVerticalScrollbar())
         return;