[js] Convert to using size instead of sentinels

This CL changes the DefineMethod, DefineProps and DefineConsts methods
to pass a size instead of depending on a sentinel value in the
definition arrays.

Change-Id: Ie054544124290c0833a8b21af175a203ca99591a
Reviewed-on: https://pdfium-review.googlesource.com/20551
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Lei Zhang <thestig@chromium.org>
diff --git a/fxjs/cjs_global.cpp b/fxjs/cjs_global.cpp
index 95124ff..2376354 100644
--- a/fxjs/cjs_global.cpp
+++ b/fxjs/cjs_global.cpp
@@ -174,8 +174,7 @@
 }  // namespace
 
 const JSMethodSpec CJS_Global::MethodSpecs[] = {
-    {"setPersistent", setPersistent_static},
-    {0, 0}};
+    {"setPersistent", setPersistent_static}};
 
 int CJS_Global::ObjDefnID = -1;
 
@@ -227,7 +226,7 @@
   ObjDefnID = pEngine->DefineObj("global", FXJSOBJTYPE_STATIC,
                                  JSConstructor<CJS_Global, JSGlobalAlternate>,
                                  JSDestructor<CJS_Global>);
-  DefineMethods(pEngine, ObjDefnID, MethodSpecs);
+  DefineMethods(pEngine, ObjDefnID, MethodSpecs, FX_ArraySize(MethodSpecs));
   DefineAllProperties(pEngine);
 }