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

Source/core/inspector/InspectorTraceEvents.h

Index: Source/core/inspector/InspectorTraceEvents.h
diff --git a/Source/core/inspector/InspectorTraceEvents.h b/Source/core/inspector/InspectorTraceEvents.h
index 4e5dbb0f396ccf696e1567ba2fa68dcaa7e2aec5..6ad952b73e89bc1b2f018c88c95fd188f8e68b50 100644
--- a/Source/core/inspector/InspectorTraceEvents.h
+++ b/Source/core/inspector/InspectorTraceEvents.h
@@ -277,9 +277,9 @@ public:
     static PassRefPtr<TraceEvent::ConvertableToTraceFormat> data(const String& sessionId, int workerId, WorkerThread*);
 };
 
-class InspectorTracingStartedInPage {
+class InspectorTracingStartedInFrame {
 public:
-    static PassRefPtr<TraceEvent::ConvertableToTraceFormat> data(const String& sessionId, Page*);
+    static PassRefPtr<TraceEvent::ConvertableToTraceFormat> data(const String& sessionId, LocalFrame*);
 };
 
 class InspectorSetLayerTreeId {