/cc @jonahwilliams @johnmccutchan @bdero

Background

Unbeknown to me, we have an e2e test in the framework covering surface_texture external textures:

1. .ci.yaml:

   flutter/.ci.yaml

   Line 2171 in e593cdf

   - name: Linux_pixel_7pro external_ui_integration_test

2. .dart runner:

   flutter/dev/devicelab/lib/tasks/integration_tests.dart

   Line 43 in e593cdf

   TaskFunction createExternalUiIntegrationTest() {

3. (actual test) https://github.com/flutter/flutter/blob/e593cdfb80975fb6a41dff21e3f4f774f7e68723/dev/integration_tests/external_ui/test_driver/main_test.dart

If working properly, it produces a picture like this:

... however, it doesn't do any pixel validation, and only runs on the Skia backend.

Tasks

• Add a pixel-validation test, likely with two filled rectangles one-inside another
• Add a resizing platform view test (Manually revert TLHC optimizations, holding on to width/height changes. engine#50144)
• Run Android in both Skia (current) and Impeller+OpenGLES (perhaps later in Vulkan)
• Rename external_ui to external_texture_integration_test to disambiguate
• Link to this test in the shell/embedder/android/README.md