Add a DevTools command to create an isolated world for a given frame

third_party/WebKit/Source/platform/bindings/DOMWrapperWorld.cpp

Index: third_party/WebKit/Source/platform/bindings/DOMWrapperWorld.cpp
diff --git a/third_party/WebKit/Source/platform/bindings/DOMWrapperWorld.cpp b/third_party/WebKit/Source/platform/bindings/DOMWrapperWorld.cpp
index 106f9d359a1550d98dddc8b8e51e0a908a22a18f..38ec443a8b96ecdaf21445cd1a133079d32e0aa1 100644
--- a/third_party/WebKit/Source/platform/bindings/DOMWrapperWorld.cpp
+++ b/third_party/WebKit/Source/platform/bindings/DOMWrapperWorld.cpp
@@ -257,6 +257,7 @@ void DOMWrapperWorld::WeakCallbackForDOMObjectHolder(
   holder_base->World()->UnregisterDOMObjectHolder(holder_base);
 }
 
+// static
 int DOMWrapperWorld::GenerateWorldIdForType(WorldType world_type) {
   DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<int>, next_world_id,
                                   new ThreadSpecific<int>);
@@ -283,6 +284,21 @@ int DOMWrapperWorld::GenerateWorldIdForType(WorldType world_type) {
   return kInvalidWorldId;
 }
 
+// static
+int DOMWrapperWorld::GetNextDevToolsIsolatedWorldId() {
+  DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<int>,

[pfeldman, 2017/05/05 15:40:24]

DCHECK(isMainThread()) + simpler static local instead?

[alex clarke (OOO till 29th), 2017/05/05 19:29:44]

Done.

+                                  next_devtools_isolated_world_id,
+                                  new ThreadSpecific<int>);
+
+  if (!next_devtools_isolated_world_id.IsSet())
+    *next_devtools_isolated_world_id = WorldId::kDevToolsFirstIsolatedWorldId;
+  int world_id = *next_devtools_isolated_world_id;
+  if (world_id > WorldId::kDevToolsLastIsolatedWorldId)
+    return WorldId::kInvalidWorldId;
+  *next_devtools_isolated_world_id = world_id + 1;
+  return world_id;
+}
+
 void DOMWrapperWorld::DissociateDOMWindowWrappersInAllWorlds(
     ScriptWrappable* script_wrappable) {
   DCHECK(script_wrappable);