Replace uses of hash_map in //base

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 45a973964231fa7d794b2be72d3175871970720b..5a0f4c5aca9e8c6a9579e98c0d01c48ed0e48a9e 100644
--- a/base/trace_event/process_memory_dump.h
+++ b/base/trace_event/process_memory_dump.h
@@ -118,11 +118,12 @@ 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,
-                     const char* allocator_name);
+  void DumpHeapUsage(
+      const std::unordered_map<base::trace_event::AllocationContext,
+                               base::trace_event::AllocationMetrics>&
+          metrics_by_context,
+      base::trace_event::TraceEventMemoryOverhead& overhead,
+      const char* allocator_name);
 
   // Adds an ownership relationship between two MemoryAllocatorDump(s) with the
   // semantics: |source| owns |target|, and has the effect of attributing