Enable gestures for wheel events on all platforms other than MacOSX.

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 b4d07233e8ccee4b0c9d6a7896e08e37ed87c4a6..ffc84fe71063f01beea8376956d299e59b783b33 100644
--- a/content/public/common/content_switches.cc
+++ b/content/public/common/content_switches.cc
@@ -293,6 +293,9 @@ const char kDisableWebSecurity[]            = "disable-web-security";
 // Disables Blink's XSSAuditor. The XSSAuditor mitigates reflective XSS.
 const char kDisableXSSAuditor[]             = "disable-xss-auditor";
 
+// Disable gesture generation for wheel events.
+const char kDisableWheelGestures[] = "disable-wheel-gestures";
+
 // Disable rasterizer that writes directly to GPU memory associated with tiles.
 const char kDisableZeroCopy[]                = "disable-zero-copy";