Fix MediaStreamDeviceObserver name in content_renderer_manifest.json

This was renamed from MediaStreamDispatcher in https://crrev.com/c/786593.

Bug: 817214
Change-Id: If3aac97652afbcf08c2ece7beb81a22534d58501
Reviewed-on: https://chromium-review.googlesource.com/941204
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#539872}(cherry picked from commit cade37d88fabb3a74b89ecdbe8398cb035c5599e)
Reviewed-on: https://chromium-review.googlesource.com/943641
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Commit-Position: refs/branch-heads/3325@{#639}
Cr-Branched-From: bc084a8b5afa3744a74927344e304c02ae54189f-refs/heads/master@{#530369}
diff --git a/content/public/app/mojo/content_renderer_manifest.json b/content/public/app/mojo/content_renderer_manifest.json
index 5efdd84..a0e53cf 100644
--- a/content/public/app/mojo/content_renderer_manifest.json
+++ b/content/public/app/mojo/content_renderer_manifest.json
@@ -56,7 +56,7 @@
           "content::mojom::ImageDownloader",
           "content::mojom::FrameInputHandler",
           "content::mojom::FullscreenVideoElementHandler",
-          "content::mojom::MediaStreamDispatcher",
+          "content::mojom::MediaStreamDeviceObserver",
           "content::mojom::Widget",
           "viz::mojom::InputTargetClient"
         ]