Unwrap optionals that already have an empty state that must be checked, like `std::optional<std::shared_ptr<T>>` and `std::optional<std::function<T>>`.

Some Android devices do not support the memory type eLazilyAllocated, which we use for MSAA and stencil textures. These textures were falling back to device local in dedicated allocations, which are expensive to both allocate and free. The dedicated allocation is implied by asking for eLazilyAllocated

Instead, perform a check for support for this memory type. Never request dedicated allocations (at least not until we have a compelling use case)

This should fix flutter/flutter#129737

flutter/flutter#129784

https://dart.googlesource.com/sdk.git/+log/ecc2440be198..2d98d9e27dae

2023-06-29 [email protected] Version 3.1.0-262.0.dev

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/dart-sdk-flutter-engine
Please CC [email protected],[email protected] on the revert to ensure that a human
is aware of the problem.

To file a bug in Flutter Engine: https://github.com/flutter/flutter/issues/new/choose

To report a problem with the AutoRoller itself, please file a bug:
https://bugs.chromium.org/p/skia/issues/entry?template=Autoroller+Bug

Documentation for the AutoRoller is here:
https://skia.googlesource.com/buildbot/+doc/main/autoroll/README.md

https://skia.googlesource.com/skia.git/+log/a1ae27969207..2d05e3ec6b67

2023-06-29 [email protected] [graphite] Add rescale support.

If this roll has caused a breakage, revert this CL and stop the roller
using the controls here:
https://autoroll.skia.org/r/skia-flutter-autoroll
Please CC [email protected],[email protected],[email protected],[email protected] on the revert to ensure that a human
is aware of the problem.

To file a bug in Skia: https://bugs.chromium.org/p/skia/issues/entry
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The linter is failing on this in my unrelated PR for some reason: #43348

```
� Failures for clang-tidy on /Volumes/Work/s/w/ir/cache/builder/src/flutter/impeller/renderer/backend/metal/vertex_descriptor_mtl.mm:
/Volumes/Work/s/w/ir/cache/builder/src/flutter/impeller/renderer/backend/metal/vertex_descriptor_mtl.mm:177:3: error: missing username/bug in TODO [google-readability-todo,-warnings-as-errors]
  // TODO: its odd that we offset buffers from the max index on metal
  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  // TODO(chrome-bot): its odd that we offset buffers from the max index on metal
Suppressed 1476 warnings (1475 in non-user code, 1 NOLINT).
Use -header-filter=.* to display errors from all non-system headers. Use -system-headers to display errors from system headers as well.
1 warning treated as error
```

Whoopsies, I missed a spot... Fix a possible crash where an optional nullptr can be provided as the backdrop filter proc. Related: #43345

This PR adds a `nonce` JS configuration attribute so users can pass a nonce value to their flutter engine initialization code.

This `nonce` is used to mark all scripts/styles needed by Flutter web that are considered `unsafe-inline` by CSP. In this change, there are only two tags that benefit from this:

* canvaskit.js
* inline styles for text editing

Before this change, the most strict CSP that allows a Flutter Web app to run would look like:

```
script-src 'self' 'nonce-flutter-init-scripts' 'wasm-unsafe-eval' https://www.gstatic.com/flutter-canvaskit/;
font-src https://fonts.gstatic.com;
style-src 'unsafe-inline';
```

After this change, CSP could be tightened to:

```
script-src 'self' 'nonce-YOUR_NONCE_VALUE' 'wasm-unsafe-eval';
font-src https://fonts.gstatic.com;
style-src 'nonce-YOUR_NONCE_VALUE';
```

By initializing the Flutter web app with something like this:

```html
<meta http-equiv="Content-Security-Policy" content="script-src 'self' 'nonce-YOUR_NONCE_VALUE' 'wasm-unsafe-eval'; font-src https://fonts.gstatic.com; style-src 'nonce-YOUR_NONCE_VALUE';">

...

<script nonce="YOUR_NONCE_VALUE">
  _flutter.loader.loadEntrypoint({
    onEntrypointLoaded: async function(engineInitializer) {
      let appRunner = await engineInitializer.initializeEngine({
        nonce: 'YOUR_NONCE_VALUE',
      });
      appRunner.runApp();
    }
  });
</script>
```

## Issues

Fixes flutter/flutter#126977 (does not address `flutter.js`, that's a [different story](flutter/flutter#128061))
Helps with flutter/flutter#80221

---

[C++, Objective-C, Java style guides]: https://github.com/flutter/engine/blob/main/CONTRIBUTING.md#style