DevTools: speculative fix of crash in PageDebuggerAgent::restore

Source/core/inspector/PageDebuggerAgent.cpp

Index: Source/core/inspector/PageDebuggerAgent.cpp
diff --git a/Source/core/inspector/PageDebuggerAgent.cpp b/Source/core/inspector/PageDebuggerAgent.cpp
index ed7dedfa2a6d2fc1522ad12b5274234e75950c82..0afdf4585fda7f8b5ef060e44d68586d3f864d3e 100644
--- a/Source/core/inspector/PageDebuggerAgent.cpp
+++ b/Source/core/inspector/PageDebuggerAgent.cpp
@@ -94,6 +94,12 @@ void PageDebuggerAgent::enable(ErrorString* errorString)
     InspectorDebuggerAgent::enable(errorString);
 }
 
+void PageDebuggerAgent::restore()
+{
+    if (canExecuteScripts())
+        InspectorDebuggerAgent::restore();
+}
+
 void PageDebuggerAgent::enable()
 {
     ASSERT(canExecuteScripts());