Cleanup remaining IFWL files for visiblity and usage.

fpdfsdk/fpdfxfa/cxfa_fwladaptertimermgr.h

Index: fpdfsdk/fpdfxfa/cxfa_fwladaptertimermgr.h
diff --git a/fpdfsdk/fpdfxfa/cxfa_fwladaptertimermgr.h b/fpdfsdk/fpdfxfa/cxfa_fwladaptertimermgr.h
index ee4b404a5cc3a58d50b9f1b8b5dc6061d1655c99..2a1c509aa343ac80c306c53c64b019c309848bca 100644
--- a/fpdfsdk/fpdfxfa/cxfa_fwladaptertimermgr.h
+++ b/fpdfsdk/fpdfxfa/cxfa_fwladaptertimermgr.h
@@ -19,11 +19,11 @@ class CXFA_FWLAdapterTimerMgr : public IFWL_AdapterTimerMgr {
   CXFA_FWLAdapterTimerMgr(CPDFSDK_FormFillEnvironment* pFormFillEnv)
       : m_pFormFillEnv(pFormFillEnv) {}
 
-  FWL_Error Start(IFWL_Timer* pTimer,
-                  uint32_t dwElapse,
-                  bool bImmediately,
-                  IFWL_TimerInfo** pTimerInfo) override;
-  FWL_Error Stop(IFWL_TimerInfo* pTimerInfo) override;
+  void Start(IFWL_Timer* pTimer,
+             uint32_t dwElapse,
+             bool bImmediately,
+             IFWL_TimerInfo** pTimerInfo) override;
+  void Stop(IFWL_TimerInfo* pTimerInfo) override;
 
  protected:
   static void TimerProc(int32_t idEvent);