Make better internal use of ContentSecurityPolicy::document()

Source/core/frame/csp/ContentSecurityPolicy.cpp

Index: Source/core/frame/csp/ContentSecurityPolicy.cpp
diff --git a/Source/core/frame/csp/ContentSecurityPolicy.cpp b/Source/core/frame/csp/ContentSecurityPolicy.cpp
index cdd5d063a27a8209e4e2fb288da86cdb7096524b..3775ccb028a34a9eeca5ac508b0e1b9cf504b93f 100644
--- a/Source/core/frame/csp/ContentSecurityPolicy.cpp
+++ b/Source/core/frame/csp/ContentSecurityPolicy.cpp
@@ -474,8 +474,7 @@ bool ContentSecurityPolicy::allowChildContextFromSource(const KURL& url, Content
 bool ContentSecurityPolicy::allowWorkerContextFromSource(const KURL& url, ContentSecurityPolicy::ReportingStatus reportingStatus) const
 {
     // CSP 1.1 moves workers from 'script-src' to the new 'child-src'. Measure the impact of this backwards-incompatible change.
-    if (m_executionContext->isDocument()) {
-        Document* document = static_cast<Document*>(m_executionContext);
+    if (Document* document = this->document()) {
         UseCounter::count(*document, UseCounter::WorkerSubjectToCSP);
         if (isAllowedByAllWithURL<&CSPDirectiveList::allowChildContextFromSource>(m_policies, url, SuppressReport) && !isAllowedByAllWithURL<&CSPDirectiveList::allowScriptFromSource>(m_policies, url, SuppressReport))
             UseCounter::count(*document, UseCounter::WorkerAllowedByChildBlockedByScript);
@@ -588,10 +587,10 @@ static void gatherSecurityPolicyViolationEventData(SecurityPolicyViolationEventI
 void ContentSecurityPolicy::reportViolation(const String& directiveText, const String& effectiveDirective, const String& consoleMessage, const KURL& blockedURL, const Vector<KURL>& reportURIs, const String& header)
 {
     // FIXME: Support sending reports from worker.
-    if (!m_executionContext->isDocument())
+    Document* document = this->document();
+    if (!document)
         return;
 
-    Document* document = this->document();
     LocalFrame* frame = document->frame();
     if (!frame)
         return;