Cleanup remaining IFWL files for visiblity and usage.

xfa/fwl/core/ifwl_adaptertimermgr.h

Index: xfa/fwl/core/ifwl_adaptertimermgr.h
diff --git a/xfa/fwl/core/ifwl_adaptertimermgr.h b/xfa/fwl/core/ifwl_adaptertimermgr.h
index ef5ebba59bbfc28531b77e99b70b80f4162264ee..156c0cf6f95aba7b297290937c131102572eb5a4 100644
--- a/xfa/fwl/core/ifwl_adaptertimermgr.h
+++ b/xfa/fwl/core/ifwl_adaptertimermgr.h
@@ -7,17 +7,16 @@
 #ifndef XFA_FWL_CORE_IFWL_ADAPTERTIMERMGR_H_
 #define XFA_FWL_CORE_IFWL_ADAPTERTIMERMGR_H_
 
-#include "xfa/fwl/core/fwl_error.h"
 #include "xfa/fwl/core/ifwl_timer.h"
 
 class IFWL_AdapterTimerMgr {
  public:
   virtual ~IFWL_AdapterTimerMgr() {}
-  virtual FWL_Error Start(IFWL_Timer* pTimer,
-                          uint32_t dwElapse,
-                          bool bImmediately,
-                          IFWL_TimerInfo** pTimerInfo) = 0;
-  virtual FWL_Error Stop(IFWL_TimerInfo* pTimerInfo) = 0;
+  virtual void Start(IFWL_Timer* pTimer,
+                     uint32_t dwElapse,
+                     bool bImmediately,
+                     IFWL_TimerInfo** pTimerInfo) = 0;
+  virtual void Stop(IFWL_TimerInfo* pTimerInfo) = 0;
 };
 
 #endif  // XFA_FWL_CORE_IFWL_ADAPTERTIMERMGR_H_