DevTools: use per-LocalFrame instrumenting agents instead of per-Page ones.

Source/core/inspector/InspectorResourceContentLoader.h

Index: Source/core/inspector/InspectorResourceContentLoader.h
diff --git a/Source/core/inspector/InspectorResourceContentLoader.h b/Source/core/inspector/InspectorResourceContentLoader.h
index d37c0c00809a436a81ca398f939307706565b532..71b57509c40d77fb2183c274fe4167377d527640 100644
--- a/Source/core/inspector/InspectorResourceContentLoader.h
+++ b/Source/core/inspector/InspectorResourceContentLoader.h
@@ -12,7 +12,7 @@
 
 namespace blink {
 
-class Page;
+class LocalFrame;
 class Resource;
 class VoidCallback;
 
@@ -20,7 +20,7 @@ class InspectorResourceContentLoader final : public NoBaseWillBeGarbageCollected
     WTF_MAKE_NONCOPYABLE(InspectorResourceContentLoader);
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
-    explicit InspectorResourceContentLoader(Page*);
+    explicit InspectorResourceContentLoader(LocalFrame*);
     void ensureResourcesContentLoaded(VoidCallback*);
     ~InspectorResourceContentLoader();
     void trace(Visitor*);
@@ -38,7 +38,7 @@ private:
     PersistentHeapVectorWillBeHeapVector<Member<VoidCallback> > m_callbacks;
     bool m_allRequestsStarted;
     bool m_started;
-    RawPtrWillBeMember<Page> m_page;
+    RawPtrWillBeMember<LocalFrame> m_inspectedFrame;
     HashSet<ResourceClient*> m_pendingResourceClients;
     Vector<ResourcePtr<Resource> > m_resources;