Support multi-button press for synthetic mouse events

content/browser/renderer_host/input/synthetic_pointer_driver.h

Index: content/browser/renderer_host/input/synthetic_pointer_driver.h
diff --git a/content/browser/renderer_host/input/synthetic_pointer_driver.h b/content/browser/renderer_host/input/synthetic_pointer_driver.h
index 32579fb88fbf615ae049dea80c54bd64cea7e86e..2bdad7d8675935e91122231c9ec5a9452dd9ff75 100644
--- a/content/browser/renderer_host/input/synthetic_pointer_driver.h
+++ b/content/browser/renderer_host/input/synthetic_pointer_driver.h
@@ -28,9 +28,9 @@ class CONTENT_EXPORT SyntheticPointerDriver {
   virtual void DispatchEvent(SyntheticGestureTarget* target,
                              const base::TimeTicks& timestamp) = 0;
 
-  virtual void Press(float x, float y, int index = 0) = 0;
+  virtual void Press(float x, float y, int index = 0, int button = 0) = 0;
   virtual void Move(float x, float y, int index = 0) = 0;
-  virtual void Release(int index = 0) = 0;
+  virtual void Release(int index = 0, int button = 0) = 0;
 
   // Check if the user inputs in the SyntheticPointerActionParams can generate
   // a valid sequence of pointer actions.