Remove uses of base::hash_map from //chrome

chrome/browser/android/compositor/tab_content_manager.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_ANDROID_COMPOSITOR_TAB_CONTENT_MANAGER_H_
 #define CHROME_BROWSER_ANDROID_COMPOSITOR_TAB_CONTENT_MANAGER_H_
 
 #include <jni.h>
 
-#include <unordered_map>
+#include <map>
 
 #include "base/android/jni_android.h"
 #include "base/android/jni_weak_ref.h"
-#include "base/containers/hash_tables.h"
+#include "base/containers/flat_map.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "cc/layers/ui_resource_layer.h"
 #include "chrome/browser/android/thumbnail/thumbnail_cache.h"
 
 using base::android::ScopedJavaLocalRef;
 
 namespace cc {
 class Layer;
 }
@@ skipping 73 matching lines @@
   void GetDecompressedThumbnail(JNIEnv* env,
                                 const base::android::JavaParamRef<jobject>& obj,
                                 jint tab_id);
   void OnUIResourcesWereEvicted();
 
   // ThumbnailCacheObserver implementation;
   void OnFinishedThumbnailRead(TabId tab_id) override;
 
  private:
   class TabReadbackRequest;
-  using LayerMap = base::hash_map<int, scoped_refptr<cc::Layer>>;
-  using ThumbnailLayerMap = base::hash_map<int, scoped_refptr<ThumbnailLayer>>;
+  // TODO(bug 714384) check sizes and consider using base::flat_map if these
+  // layer maps are small.
+  using LayerMap = std::map<int, scoped_refptr<cc::Layer>>;
+  using ThumbnailLayerMap = std::map<int, scoped_refptr<ThumbnailLayer>>;
   using TabReadbackRequestMap =
-      std::unordered_map<int, std::unique_ptr<TabReadbackRequest>>;
+      base::flat_map<int, std::unique_ptr<TabReadbackRequest>>;
 
   void PutThumbnailIntoCache(int tab_id,
                              float thumbnail_scale,
                              const SkBitmap& bitmap);
 
   std::unique_ptr<ThumbnailCache> thumbnail_cache_;
   ThumbnailLayerMap static_layer_cache_;
   LayerMap live_layer_list_;
   TabReadbackRequestMap pending_tab_readbacks_;
 
   JavaObjectWeakGlobalRef weak_java_tab_content_manager_;
   base::WeakPtrFactory<TabContentManager> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContentManager);
 };
 
 bool RegisterTabContentManager(JNIEnv* env);
 
 }  // namespace android
 
 #endif  // CHROME_BROWSER_ANDROID_COMPOSITOR_TAB_CONTENT_MANAGER_H_