Move the ScriptForbiddenScope in TreeScope::adoptIfNeeded to the top of the function.

third_party/WebKit/Source/core/dom/TreeScope.cpp

Index: third_party/WebKit/Source/core/dom/TreeScope.cpp
diff --git a/third_party/WebKit/Source/core/dom/TreeScope.cpp b/third_party/WebKit/Source/core/dom/TreeScope.cpp
index 2d1a1b6ee5785db7a5b02c61938eccb91f118cdc..8cd9b55c0c6594d1f5f6431034aad64b078585bc 100644
--- a/third_party/WebKit/Source/core/dom/TreeScope.cpp
+++ b/third_party/WebKit/Source/core/dom/TreeScope.cpp
@@ -370,13 +370,14 @@ Element* TreeScope::findAnchor(const String& name)
 
 void TreeScope::adoptIfNeeded(Node& node)
 {
+    // Script is forbidden to protect against event handlers firing in the middle of rescoping
+    // in |didMoveToNewDocument| callbacks. See https://crbug.com/605766 and https://crbug.com/606651.
+    ScriptForbiddenScope forbidScript;
     DCHECK(this);
     DCHECK(!node.isDocumentNode());
     TreeScopeAdopter adopter(node, *this);
-    if (adopter.needsScopeChange()) {
-        ScriptForbiddenScope forbidScript;
+    if (adopter.needsScopeChange())
         adopter.execute();
-    }
 }
 
 Element* TreeScope::retarget(const Element& target) const