Demote CompositeSVG to experimental

We still have several bugs about transform animation to fix.

[email protected]

(cherry picked from commit 914c047313f7dbb8122aa27158dbba9b30140975)

Bug: 1101002
Change-Id: I8ca37e70fd0391ee3b43c5e63e3436b810e169c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2471817
Reviewed-by: Philip Rogers <[email protected]>
Commit-Queue: Xianzhu Wang <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#817219}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2482325
Reviewed-by: Xianzhu Wang <[email protected]>
Cr-Commit-Position: refs/branch-heads/4280@{#460}
Cr-Branched-From: ea420fb963f9658c9969b6513c56b8f47efa1a2a-refs/heads/master@{#812852}
diff --git a/third_party/blink/renderer/platform/runtime_enabled_features.json5 b/third_party/blink/renderer/platform/runtime_enabled_features.json5
index b498d0cc..47c483b7 100644
--- a/third_party/blink/renderer/platform/runtime_enabled_features.json5
+++ b/third_party/blink/renderer/platform/runtime_enabled_features.json5
@@ -336,7 +336,7 @@
     },
     {
       name: "CompositeSVG",
-      status: "stable"
+      status: "experimental",
     },
     {
       name: "CompositingOptimizations",