Merge to XFA: Ensure functions in FXJS_V8 are prefixed by FXJS_.

Manual edits:
  fpdfsdk/include/javascript/JS_Define.h
  fpdfsdk/src/fpdfxfa/fpdfxfa_app.cpp
  fpdfsdk/src/javascript/Document.cpp
  fpdfsdk/src/javascript/JS_Runtime.cpp
  fpdfsdk/src/jsapi/fxjs_v8.cpp

(cherry picked from commit 506df426d5d64d68e9dc27ffebcf56f6c6a1bccf)
Original Review URL: https://codereview.chromium.org/1347833002 .

(cherry picked from commit 455019ca48f60bd285e043986471f51f17c69a0d)
Original Review URL: https://codereview.chromium.org/1349783003 .

(cherry picked from commit 1af240cc45480520b447be767686e73a29c48f9e)
Original Review URL: https://codereview.chromium.org/1348693003 .

R=thestig@chromium.org

Review URL: https://codereview.chromium.org/1356563003 .
diff --git a/fpdfsdk/src/javascript/JS_Context.cpp b/fpdfsdk/src/javascript/JS_Context.cpp
index 3c9be58..d4d1f2c 100644
--- a/fpdfsdk/src/javascript/JS_Context.cpp
+++ b/fpdfsdk/src/javascript/JS_Context.cpp
@@ -56,8 +56,8 @@
   FXJSErr error = {NULL, NULL, 0};
   int nRet = 0;
   if (script.GetLength() > 0) {
-    nRet = JS_Execute(m_pRuntime->GetIsolate(), this, script.c_str(),
-                      script.GetLength(), &error);
+    nRet = FXJS_Execute(m_pRuntime->GetIsolate(), this, script.c_str(),
+                        script.GetLength(), &error);
   }
 
   if (nRet < 0) {