[tracing] Switch to new heap dump format.

base/trace_event/process_memory_dump.h

Index: base/trace_event/process_memory_dump.h
diff --git a/base/trace_event/process_memory_dump.h b/base/trace_event/process_memory_dump.h
index 6f8d167273327e2488ae30f12ca53928c810543d..ff901a519568b2180c37719cfd59eb1d2aad22f4 100644
--- a/base/trace_event/process_memory_dump.h
+++ b/base/trace_event/process_memory_dump.h
@@ -31,6 +31,7 @@
 namespace base {
 namespace trace_event {
 
+class AllocationRegister;
 class MemoryDumpSessionState;
 class TracedValue;
 
@@ -118,10 +119,7 @@ class BASE_EXPORT ProcessMemoryDump {
   const AllocatorDumpsMap& allocator_dumps() const { return allocator_dumps_; }
 
   // Dumps heap usage with |allocator_name|.
-  void DumpHeapUsage(const base::hash_map<base::trace_event::AllocationContext,
-                                          base::trace_event::AllocationMetrics>&
-                         metrics_by_context,
-                     base::trace_event::TraceEventMemoryOverhead& overhead,
+  void DumpHeapUsage(const AllocationRegister& allocation_register,
                      const char* allocator_name);
 
   // Adds an ownership relationship between two MemoryAllocatorDump(s) with the