Dump /proc/<pid>/maps with every heap profile dump.

third_party/tcmalloc/chromium/src/deep-heap-profile.h

Index: third_party/tcmalloc/chromium/src/deep-heap-profile.h
diff --git a/third_party/tcmalloc/chromium/src/deep-heap-profile.h b/third_party/tcmalloc/chromium/src/deep-heap-profile.h
index be213b26c8f110ae35a04c79600041ebb01fc8d0..37f9bbcdb8cf0420b76d88a38ec3ff01e33577a6 100644
--- a/third_party/tcmalloc/chromium/src/deep-heap-profile.h
+++ b/third_party/tcmalloc/chromium/src/deep-heap-profile.h
@@ -196,9 +196,12 @@ class DeepHeapProfile {
                                  uint64 first_address,
                                  uint64 last_address);
 
-  // Write re-formatted /proc/self/maps into a file which has |filename_prefix|
-  // with using |buffer| of size |buffer_size|.
+  // Write re-formatted /proc/self/maps into a file with using |buffer| of
+  // size |buffer_size|.
+  // If |count| is zero, the filename will be "|filename_prefix|.<pid>.maps".
+  // Otherwise, "|filename_prefix|.<pid>.|count|.maps".
   static void WriteMapsToFile(const char* filename_prefix,
+                              unsigned count,
                               int buffer_size,
                               char buffer[]);