Make it possible for the scroll offset delegate to intercept fling.

content/public/common/content_switches.cc

Index: content/public/common/content_switches.cc
diff --git a/content/public/common/content_switches.cc b/content/public/common/content_switches.cc
index 88ee98c17173847579862c3494423485d3e5c81e..b2a9766c01a7f2f3a12e8b50573a58d652a33bb0 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -545,6 +545,10 @@ const char kGpuVendorID[]                   = "gpu-vendor-id";
 // Don't display any scrollbars. This is useful for Android WebView where
 // the system manages the scrollbars instead.
 const char kHideScrollbars[]                = "hide-scrollbars";
+
+// Don't process fling gestures targeted at the root scroll layer. This is
+// useful for the Android WebView which handles the fling animations itself.
+const char kIgnoreRootLayerFlings[]         = "ignore-root-layer-flings";
 #endif
 
 // These mappings only apply to the host resolver.