New flingCancel flag to prevent fling boosting.

public/web/WebInputEvent.h

Index: public/web/WebInputEvent.h
diff --git a/public/web/WebInputEvent.h b/public/web/WebInputEvent.h
index 20d4785044c950bebc586ddb37100ed00def649b..85cb273208a65348ec467b25e7933af7c89bc231 100644
--- a/public/web/WebInputEvent.h
+++ b/public/web/WebInputEvent.h
@@ -468,6 +468,12 @@ public:
         } flingStart;
 
         struct {
+            // Don't treat flingCancel as a part of fling boost

[Rick Byers, 2014/12/10 19:01:01]

Nit: Add "if true" since we don't want to imply that most flingCancel events
will have this set.

+            // events sequence.
+            bool preventBoosting;
+        } flingCancel;
+
+        struct {
             float scale;
         } pinchUpdate;
     } data;