Reland "[DevTools]: Moves common to ES modules"

This reverts commit 25a9b3bd7404d49e55772ffba046ed8df65ad14e.

Reason for revert: Memory snapshots work again

Original change's description:
> Revert "[DevTools]: Moves common to ES modules"
>
> This reverts commit e064553334d4b0c925f0b1f0e2e0234be66b71be.
>
> Reason for revert: Memory tool fails to take heap snapshots with this
> error: https://imgur.com/hzR9Eqw
>
> Original change's description:
> > [DevTools]: Moves common to ES modules
> >
> > This CL converts the contents of the common/ folder over to ES modules
> > from the current custom module system. It includes statements in each
> > file that will pollute the global namespace, allowing the non-ESM code
> > to continue working as before.
> >
> > Bug: 1006759
> > Change-Id: Ib591e49155000381f85999a5da6c467ad0160996
> > Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1816563
> > Reviewed-by: Yang Guo <yangguo@chromium.org>
> > Commit-Queue: Paul Lewis <aerotwist@chromium.org>
> > Cr-Commit-Position: refs/heads/master@{#699728}
>
>
> Change-Id: Ic0d526780451e8bb4de538f11c85859a3badfb0f
> No-Presubmit: true
> No-Tree-Checks: true
> No-Try: true
> Bug: 1006759
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1825463
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Yang Guo <yangguo@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#699835}

Bug: 1006759
Change-Id: I48c7e84262bb295e5830cac8a79a274226df046c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1825420
Commit-Queue: Paul Lewis <aerotwist@chromium.org>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#699981}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 75a39ca7ac8dcfc6a830db07a5a389ca9ab27b1d
diff --git a/scripts/compile_frontend.py b/scripts/compile_frontend.py
index 9a3eb88..0f251eb 100755
--- a/scripts/compile_frontend.py
+++ b/scripts/compile_frontend.py
@@ -279,9 +279,9 @@
         '--externs',
         namespace_externs_path,
         '--js',
-        RUNTIME_FILE,
-        '--js',
         ROOT_MODULE_FILE,
+        '--js',
+        RUNTIME_FILE,
     ]
 
     all_files = descriptors.all_compiled_files()
@@ -318,7 +318,6 @@
     namespace_externs_file = tempfile.NamedTemporaryFile(mode='wt', delete=False)
     try:
         for namespace in namespaces:
-            namespace_externs_file.write('/** @const */\n')
             namespace_externs_file.write('var %s = {};\n' % namespace)
     finally:
         namespace_externs_file.close()