[UMA] Use proper C++ objects to serialize tracked_objects across process boundaries.

content/public/browser/profiler_subscriber.h

Index: content/public/browser/profiler_subscriber.h
diff --git a/content/public/browser/profiler_subscriber.h b/content/public/browser/profiler_subscriber.h
index f37947a0d067a297d279fa3e295bad11c43ef55b..a58f49e3a0d4bcc54877e32fa9fc01770ea43b0b 100644
--- a/content/public/browser/profiler_subscriber.h
+++ b/content/public/browser/profiler_subscriber.h
@@ -6,9 +6,10 @@
 #define CONTENT_PUBLIC_BROWSER_PROFILER_SUBSCRIBER_H_
 
 #include "content/common/content_export.h"
+#include "content/public/common/serialized_profiler_data.h"
 
-namespace base {
-class DictionaryValue;
+namespace tracked_objects {
+class DataCollector;
 }
 
 namespace content {
@@ -19,16 +20,16 @@ class CONTENT_EXPORT ProfilerSubscriber {
   virtual ~ProfilerSubscriber() {}
 
   // Send number of pending processes to subscriber. |end| is set to true if it
-  // is the last time. This is called on UI thread.
+  // is the last time. This is called on the UI thread.
   virtual void OnPendingProcesses(int sequence_number,
                                   int pending_processes,
                                   bool end) = 0;
 
   // Send profiler_data back to subscriber.
-  // This is called on UI thread.
+  // This is called on the UI thread.
   virtual void OnProfilerDataCollected(
       int sequence_number,
-      base::DictionaryValue* profiler_data) = 0;
+      const SerializedProfilerData& profiler_data) = 0;
 };
 
 }  // namespace content