XFA: contention between FXJSE and FXJS over isolate data slots

xfa/src/fxjse/src/runtime.cpp

Index: xfa/src/fxjse/src/runtime.cpp
diff --git a/xfa/src/fxjse/src/runtime.cpp b/xfa/src/fxjse/src/runtime.cpp
index a7ee67bc2a7d1978ae2914584c4c0d15cd85622d..7943c68480f406ea9600f53c7969b5c23e589984 100644
--- a/xfa/src/fxjse/src/runtime.cpp
+++ b/xfa/src/fxjse/src/runtime.cpp
@@ -9,6 +9,9 @@
 #include "runtime.h"
 #include "scope_inline.h"
 
+// TODO(tsepez): unify embedder data slot usage.
+static const unsigned int kFXJSEEmbedderDataSlot = 1u;
+
 // Duplicates fpdfsdk's JS_Runtime.h, but keeps XFA from depending on it.
 // TODO(tsepez): make a single version of this.
 class FXJSE_ArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
@@ -38,10 +41,10 @@ void FXJSE_Initialize() {
 static void FXJSE_Runtime_DisposeCallback(v8::Isolate* pIsolate) {
   {
     v8::Locker locker(pIsolate);
-    CFXJSE_RuntimeData* pRuntimeData =
-        reinterpret_cast<CFXJSE_RuntimeData*>(pIsolate->GetData(0));
+    CFXJSE_RuntimeData* pRuntimeData = reinterpret_cast<CFXJSE_RuntimeData*>(
+        pIsolate->GetData(kFXJSEEmbedderDataSlot));
     if (pRuntimeData) {
-      pIsolate->SetData(0, NULL);
+      pIsolate->SetData(kFXJSEEmbedderDataSlot, NULL);
       delete pRuntimeData;
     }
   }
@@ -73,7 +76,6 @@ void FXJSE_Runtime_Release(FXJSE_HRUNTIME hRuntime) {
 }
 CFXJSE_RuntimeData* CFXJSE_RuntimeData::Create(v8::Isolate* pIsolate) {
   CFXJSE_RuntimeData* pRuntimeData = new CFXJSE_RuntimeData(pIsolate);
-  ASSERT(pRuntimeData);
   CFXJSE_ScopeUtil_IsolateHandle scope(pIsolate);
   v8::Local<v8::FunctionTemplate> hFuncTemplate =
       v8::FunctionTemplate::New(pIsolate);
@@ -85,13 +87,12 @@ CFXJSE_RuntimeData* CFXJSE_RuntimeData::Create(v8::Isolate* pIsolate) {
   return pRuntimeData;
 }
 CFXJSE_RuntimeData* CFXJSE_RuntimeData::Get(v8::Isolate* pIsolate) {
-  ASSERT(pIsolate);
-  CFXJSE_RuntimeData* pRuntimeData =
-      static_cast<CFXJSE_RuntimeData*>(pIsolate->GetData(0));
+  CFXJSE_RuntimeData* pRuntimeData = static_cast<CFXJSE_RuntimeData*>(
+      pIsolate->GetData(kFXJSEEmbedderDataSlot));
   if (!pRuntimeData) {
     pRuntimeData = CFXJSE_RuntimeData::Create(pIsolate);
     ASSERT(pRuntimeData);
-    pIsolate->SetData(0, pRuntimeData);
+    pIsolate->SetData(kFXJSEEmbedderDataSlot, pRuntimeData);
   }
   return pRuntimeData;
 }