Include time.h on wasm.

Bug: chromium:804907
Change-Id: Id9b496f14134631d3308c073b8780bf18c2305c8
Reviewed-on: https://pdfium-review.googlesource.com/25270
Reviewed-by: dsinclair <dsinclair@chromium.org>
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
diff --git a/core/fxcrt/cfx_datetime.cpp b/core/fxcrt/cfx_datetime.cpp
index 04fa8a5..9dcf632 100644
--- a/core/fxcrt/cfx_datetime.cpp
+++ b/core/fxcrt/cfx_datetime.cpp
@@ -8,7 +8,7 @@
 #include "core/fxcrt/fx_system.h"
 
 #if _FX_OS_ == _FX_OS_LINUX_ || _FX_OS_ == _FX_OS_ANDROID_ || \
-    _FX_OS_ == _FX_OS_MACOSX_
+    _FX_OS_ == _FX_OS_MACOSX_ || _FX_OS_ == _FX_OS_WASM_
 #include <sys/time.h>
 #include <time.h>
 #endif