Use const ref for LocalFrame::LocalFrameRoot and FrameTree::Top

third_party/WebKit/Source/core/loader/MixedContentChecker.cpp

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 122 matching lines @@
       return "XMLHttpRequest endpoint";
     case WebURLRequest::kRequestContextXSLT:
       return "XSLT";
   }
   NOTREACHED();
   return "resource";
 }
 
 }  // namespace
 
-static void MeasureStricterVersionOfIsMixedContent(Frame* frame,
+static void MeasureStricterVersionOfIsMixedContent(Frame& frame,
                                                    const KURL& url) {
   // We're currently only checking for mixed content in `https://*` contexts.
   // What about other "secure" contexts the SchemeRegistry knows about? We'll
   // use this method to measure the occurrence of non-webby mixed content to
   // make sure we're not breaking the world without realizing it.
-  SecurityOrigin* origin = frame->GetSecurityContext()->GetSecurityOrigin();
+  SecurityOrigin* origin = frame.GetSecurityContext()->GetSecurityOrigin();
   if (MixedContentChecker::IsMixedContent(origin, url)) {
     if (origin->Protocol() != "https") {
       UseCounter::Count(
-          frame,
+          &frame,
           UseCounter::kMixedContentInNonHTTPSFrameThatRestrictsMixedContent);
     }
   } else if (!SecurityOrigin::IsSecure(url) &&
              SchemeRegistry::ShouldTreatURLSchemeAsSecure(origin->Protocol())) {
     UseCounter::Count(
-        frame,
+        &frame,
         UseCounter::kMixedContentInSecureFrameThatDoesNotRestrictMixedContent);
   }
 }
 
 bool RequestIsSubframeSubresource(Frame* frame,
                                   WebURLRequest::FrameType frame_type) {
   return (frame && frame != frame->Tree().Top() &&
           frame_type != WebURLRequest::kFrameTypeNested);
 }
 
@@ skipping 25 matching lines @@
 Frame* MixedContentChecker::InWhichFrameIsContentMixed(
     Frame* frame,
     WebURLRequest::FrameType frame_type,
     const KURL& url) {
   // We only care about subresource loads; top-level navigations cannot be mixed
   // content. Neither can frameless requests.
   if (frame_type == WebURLRequest::kFrameTypeTopLevel || !frame)
     return nullptr;
 
   // Check the top frame first.
-  if (Frame* top = frame->Tree().Top()) {
-    MeasureStricterVersionOfIsMixedContent(top, url);
-    if (IsMixedContent(top->GetSecurityContext()->GetSecurityOrigin(), url))
-      return top;
-  }
+  Frame& top = frame->Tree().Top();
+  MeasureStricterVersionOfIsMixedContent(top, url);
+  if (IsMixedContent(top.GetSecurityContext()->GetSecurityOrigin(), url))
+    return ⊤
 
-  MeasureStricterVersionOfIsMixedContent(frame, url);
+  MeasureStricterVersionOfIsMixedContent(*frame, url);
   if (IsMixedContent(frame->GetSecurityContext()->GetSecurityOrigin(), url))
     return frame;
 
   // No mixed content, no problem.
   return nullptr;
 }
 
 // static
 void MixedContentChecker::LogToConsoleAboutFetch(
     LocalFrame* frame,
@@ skipping 411 matching lines @@
   }
 
   bool strict_mixed_content_checking_for_plugin =
       mixed_frame->GetSettings() &&
       mixed_frame->GetSettings()->GetStrictMixedContentCheckingForPlugin();
   return WebMixedContent::ContextTypeFromRequestContext(
       request.GetRequestContext(), strict_mixed_content_checking_for_plugin);
 }
 
 }  // namespace blink