Remove uses of base::hash_map from //chrome

chrome/browser/memory/tab_manager_delegate_chromeos.h

Index: chrome/browser/memory/tab_manager_delegate_chromeos.h
diff --git a/chrome/browser/memory/tab_manager_delegate_chromeos.h b/chrome/browser/memory/tab_manager_delegate_chromeos.h
index 025877c84e83a2d254aafd7f0deeafec94b425b4..3a7edd319d3deb4e3a54ec910b37b98ca5a201d2 100644
--- a/chrome/browser/memory/tab_manager_delegate_chromeos.h
+++ b/chrome/browser/memory/tab_manager_delegate_chromeos.h
@@ -10,7 +10,7 @@
 #include <utility>
 #include <vector>
 
-#include "base/containers/hash_tables.h"
+#include "base/containers/flat_map.h"
 #include "base/gtest_prod_util.h"
 #include "base/logging.h"
 #include "base/macros.h"
@@ -127,10 +127,10 @@ class TabManagerDelegate : public aura::client::ActivationChangeObserver,
   typedef std::pair<int, base::ProcessHandle> ProcessInfo;
 
   // Cache OOM scores in memory.
-  typedef base::hash_map<base::ProcessHandle, int> ProcessScoreMap;
+  typedef base::flat_map<base::ProcessHandle, int> ProcessScoreMap;
 
   // A map from an ARC process name to a monotonic timestamp when it's killed.
-  typedef base::hash_map<std::string, base::TimeTicks> KilledArcProcessesMap;
+  typedef base::flat_map<std::string, base::TimeTicks> KilledArcProcessesMap;
 
   // Get the list of candidates to kill, sorted by descending importance.
   static std::vector<Candidate> GetSortedCandidates(