[Extensions Cleanup] Remove unnecessary typedef in extension_messages.h

extension_messages.h included a typedef for SubstitutionMap, which
mimicked MessageBundle::SubstitutionMap (each a
std::map<std::string, std::string>). Instead, just include
message_bundle.h in extension_messages.h, and remove the extra typedef.

Bug: None
Change-Id: I1a076b7dd8f45f774296dcf2cd64fa3ea2960356
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2528092
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Auto-Submit: Devlin <rdevlin.cronin@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825956}

extensions/common/extension_messages.h

@@ -32,6 +32,7 @@
 #include "extensions/common/extension.h"
 #include "extensions/common/extensions_client.h"
 #include "extensions/common/host_id.h"
+#include "extensions/common/message_bundle.h"
 #include "extensions/common/permissions/permission_set.h"
 #include "extensions/common/permissions/socket_permission_data.h"
 #include "extensions/common/permissions/usb_device_permission_data.h"
@@ -329,11 +330,6 @@ IPC_STRUCT_END()
 #ifndef INTERNAL_EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
 #define INTERNAL_EXTENSIONS_COMMON_EXTENSION_MESSAGES_H_
 
-// IPC_MESSAGE macros choke on extra , in the std::map, when expanding. We need
-// to typedef it to avoid that.
-// Substitution map for l10n messages.
-typedef std::map<std::string, std::string> SubstitutionMap;
-
 // Map of extensions IDs to the executing script paths.
 typedef std::map<std::string, std::set<std::string> > ExecutingScriptsMap;
 
@@ -863,9 +859,10 @@ IPC_MESSAGE_CONTROL2(ExtensionHostMsg_PostMessage,
                      extensions::Message)
 
 // Used to get the extension message bundle.
-IPC_SYNC_MESSAGE_CONTROL1_1(ExtensionHostMsg_GetMessageBundle,
-                            std::string /* extension id */,
-                            SubstitutionMap /* message bundle */)
+IPC_SYNC_MESSAGE_CONTROL1_1(
+    ExtensionHostMsg_GetMessageBundle,
+    std::string /* extension id */,
+    extensions::MessageBundle::SubstitutionMap /* message bundle */)
 
 // Sent from the renderer to the browser to return the script running result.
 IPC_MESSAGE_ROUTED4(