Switch on_device_model image type to BitmapWithArbitraryBpp

Some of the types from the on-device model service may end up getting
used in third_party/blink/public/mojom/ai/ai_language_model.mojom to
reduce duplication and simplify the implementation. In this case, calls
may be made from the renderer using these types. This switches to a
renderer-safe version of bitmap instead of the trusted type.

Bug: 415808003
Change-Id: Ia9874bcdefb25d3b45b93944a5f4854e20ec4f6e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6542128
Reviewed-by: Alex Gough <ajgo@chromium.org>
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1459621}

services/on_device_model/public/mojom/on_device_model.mojom

@@ -154,9 +154,8 @@ union InputPiece {
   // Text to be provided as input.
   string text;
   // Bitmap provided as input. This is not ImageSkia because there is no desire
-  // to support multiple scale factors. The bitmap is supplied by the
-  // browser process.
-  skia.mojom.BitmapMappedFromTrustedProcess bitmap;
+  // to support multiple scale factors.
+  skia.mojom.BitmapWithArbitraryBpp bitmap;
 
   // Used to handle version skew.
   [Default]