Migrate extensions/ to ESM

Bug: 1006759
Change-Id: I55ff55840cbf00a108cb0f3630cf5b489bf3aac2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1849386
Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Tim van der Lippe <tvanderlippe@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#704574}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: a332bbea8c8a4c485dc20685b810c082c14a7b70
diff --git a/scripts/build/generate_devtools_extension_api.py b/scripts/build/generate_devtools_extension_api.py
index 6d5728b..0eb10bc 100755
--- a/scripts/build/generate_devtools_extension_api.py
+++ b/scripts/build/generate_devtools_extension_api.py
@@ -42,7 +42,7 @@
         var tabId;
         var extensionInfo = {};
         var extensionServer;
-        platformExtensionAPI(injectedExtensionAPI("remote-" + window.parent.frames.length));
+        platformExtensionAPI(self.injectedExtensionAPI("remote-" + window.parent.frames.length));
     })();""")