Revert "Remove window.postMessage(message, transferables, targetOrigin) legacy overload"

third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp

Index: third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp b/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
index 245e99622626568027ba607f3571a8a8ca108f30..d7c0f26d43f625e1156c65fc56020f0ab9cebb26 100644
--- a/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/custom/V8WindowCustom.cpp
@@ -153,6 +153,14 @@ void V8Window::openerAttributeSetterCustom(v8::Local<v8::Value> value, const v8:
     }
 }
 
+static bool isLegacyTargetOriginDesignation(v8::Local<v8::Value> value)
+{
+    if (value->IsString() || value->IsStringObject())
+        return true;
+    return false;
+}
+
+
 void V8Window::postMessageMethodCustom(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "postMessage", "Window", info.Holder(), info.GetIsolate());
@@ -182,22 +190,25 @@ void V8Window::postMessageMethodCustom(const v8::FunctionCallbackInfo<v8::Value>
     }
 
     // This function has variable arguments and can be:
+    // Per current spec:
     //   postMessage(message, targetOrigin)
     //   postMessage(message, targetOrigin, {sequence of transferrables})
-    // TODO(foolip): Type checking of the arguments should happen in order, so
-    // that e.g. postMessage({}, { toString: () => { throw Error(); } }, 0)
-    // throws the Error from toString, not the TypeError for argument 3.
+    // Legacy non-standard implementations in webkit allowed:
+    //   postMessage(message, {sequence of transferrables}, targetOrigin);
     Transferables transferables;
-    const int targetOriginArgIndex = 1;
+    int targetOriginArgIndex = 1;
     if (info.Length() > 2) {
-        const int transferablesArgIndex = 2;
+        int transferablesArgIndex = 2;
+        if (isLegacyTargetOriginDesignation(info[2])) {
+            Deprecation::countDeprecationIfNotPrivateScript(info.GetIsolate(), window->document(), UseCounter::WindowPostMessageWithLegacyTargetOriginArgument);
+            targetOriginArgIndex = 2;
+            transferablesArgIndex = 1;
+        }
         if (!SerializedScriptValue::extractTransferables(info.GetIsolate(), info[transferablesArgIndex], transferablesArgIndex, transferables, exceptionState)) {
             exceptionState.throwIfNeeded();
             return;
         }
     }
-    // TODO(foolip): targetOrigin should be a USVString in IDL and treated as
-    // such here, without TreatNullAndUndefinedAsNullString.
     TOSTRING_VOID(V8StringResource<TreatNullAndUndefinedAsNullString>, targetOrigin, info[targetOriginArgIndex]);
 
     RefPtr<SerializedScriptValue> message = SerializedScriptValue::serialize(info.GetIsolate(), info[0], &transferables, nullptr, exceptionState);