fix: use context counter as contextId

For sandboxed renderer it may not have a node::Environment in the context,
using a increasing counter as contextId works for all cases.

atom/common/api/atom_api_v8_util.cc

@@ -12,20 +12,10 @@
 #include "atom/common/native_mate_converters/gurl_converter.h"
 #include "atom/common/node_includes.h"
 #include "base/hash.h"
-#include "base/process/process_handle.h"
-#include "base/strings/stringprintf.h"
 #include "native_mate/dictionary.h"
 #include "url/origin.h"
 #include "v8/include/v8-profiler.h"
 
-// This is defined in later versions of Chromium, remove this if you see
-// compiler complaining duplicate defines.
-#if defined(OS_WIN) || defined(OS_FUCHSIA)
-#define CrPRIdPid "ld"
-#else
-#define CrPRIdPid "d"
-#endif
-
 namespace std {
 
 // The hash function used by DoubleIDWeakMap.
@@ -100,16 +90,6 @@ int32_t GetObjectHash(v8::Local<v8::Object> object) {
   return object->GetIdentityHash();
 }
 
-std::string GetContextID(v8::Isolate* isolate) {
-  // When a page is reloaded, V8 and blink may have optimizations that do not
-  // free blink::WebLocalFrame and v8::Context and reuse them for the new page,
-  // while we always recreate node::Environment when a page is loaded.
-  // So the only reliable way to return an identity for a page, is to return the
-  // address of the node::Environment instance.
-  node::Environment* env = node::Environment::GetCurrent(isolate);
-  return base::StringPrintf("%" CrPRIdPid "-%p", base::GetCurrentProcId(), env);
-}
-
 void TakeHeapSnapshot(v8::Isolate* isolate) {
   isolate->GetHeapProfiler()->TakeHeapSnapshot();
 }
@@ -132,7 +112,6 @@ void Initialize(v8::Local<v8::Object> exports,
   dict.SetMethod("setHiddenValue", &SetHiddenValue);
   dict.SetMethod("deleteHiddenValue", &DeleteHiddenValue);
   dict.SetMethod("getObjectHash", &GetObjectHash);
-  dict.SetMethod("getContextId", &GetContextID);
   dict.SetMethod("takeHeapSnapshot", &TakeHeapSnapshot);
   dict.SetMethod("setRemoteCallbackFreer", &atom::RemoteCallbackFreer::BindTo);
   dict.SetMethod("setRemoteObjectFreer", &atom::RemoteObjectFreer::BindTo);

atom/common/context_counter.cc

@@ -0,0 +1,19 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#include "atom/common/context_counter.h"
+
+namespace atom {
+
+namespace {
+
+int g_context_id = 0;
+
+}  // namespace
+
+int GetNextContextId() {
+  return ++g_context_id;
+}
+
+}  // namespace atom

atom/common/context_counter.h

@@ -0,0 +1,15 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_COMMON_CONTEXT_COUNTER_H_
+#define ATOM_COMMON_CONTEXT_COUNTER_H_
+
+namespace atom {
+
+// Increase the context counter, and return current count.
+int GetNextContextId();
+
+}  // namespace atom
+
+#endif  // ATOM_COMMON_CONTEXT_COUNTER_H_