Add new wired memory metric to memory-infra dumps.

base/process/process_metrics.h

Index: base/process/process_metrics.h
diff --git a/base/process/process_metrics.h b/base/process/process_metrics.h
index 33cb64e24430f4bacf29d7a1ea8d3f873476f6d4..b7a7b01ac8c474d12cc3329131523ee4427c80dc 100644
--- a/base/process/process_metrics.h
+++ b/base/process/process_metrics.h
@@ -154,10 +154,13 @@ class BASE_EXPORT ProcessMetrics {
   // system call.
   bool GetCommittedAndWorkingSetKBytes(CommittedKBytes* usage,
                                        WorkingSetKBytes* ws_usage) const;
-  // Returns private, shared, and total resident bytes.
+  // Returns private, shared, and total resident bytes. |locked_bytes| refers to
+  // bytes that must stay resident. |locked_bytes| only counts bytes locked by
+  // this task, not bytes locked by the kernel.
   bool GetMemoryBytes(size_t* private_bytes,
                       size_t* shared_bytes,
-                      size_t* resident_bytes) const;
+                      size_t* resident_bytes,
+                      size_t* locked_bytes) const;
 #endif
 
   // Returns the CPU usage in percent since the last time this method or