minidump: Add InitializeFromSnapshot() for MinidumpModuleCrashpadInfoListWriter and downstream

minidump/minidump_simple_string_dictionary_writer.h

Index: minidump/minidump_simple_string_dictionary_writer.h
diff --git a/minidump/minidump_simple_string_dictionary_writer.h b/minidump/minidump_simple_string_dictionary_writer.h
index 17075fe1835fbf4da72512f8bb136eb9d32ac897..d7a0b59da2271362fb4a768dd3d6d79748903bf2 100644
--- a/minidump/minidump_simple_string_dictionary_writer.h
+++ b/minidump/minidump_simple_string_dictionary_writer.h
@@ -91,6 +91,16 @@ class MinidumpSimpleStringDictionaryWriter final
   MinidumpSimpleStringDictionaryWriter();
   ~MinidumpSimpleStringDictionaryWriter() override;
 
+  //! \brief Adds an initialized MinidumpSimpleStringDictionaryEntryWriter for
+  //!     each key-value pair in \a map to the MinidumpSimpleStringDictionary.
+  //!
+  //! \param[in] map The map to use as source data.
+  //!
+  //! \note Valid in #kStateMutable. No mutator methods may be called before
+  //!     this method, and it is not normally necessary to call any mutator
+  //!     methods after this method.
+  void InitializeFromMap(const std::map<std::string, std::string>& map);
+
   //! \brief Adds a MinidumpSimpleStringDictionaryEntryWriter to the
   //!     MinidumpSimpleStringDictionary.
   //!
@@ -104,6 +114,15 @@ class MinidumpSimpleStringDictionaryWriter final
   //! \note Valid in #kStateMutable.
   void AddEntry(scoped_ptr<MinidumpSimpleStringDictionaryEntryWriter> entry);
 
+  //! \brief Determines whether the object is useful.
+  //!
+  //! A useful object is one that carries data that makes a meaningful
+  //! contribution to a minidump file. An object carrying entries would be
+  //! considered useful.
+  //!
+  //! \return `true` if the object is useful, `false` otherwise.
+  bool IsUseful() const;
+
  protected:
   // MinidumpWritable: