Auto merge of #24242 - jdm:xr-webgllayer-format, r=asajeffrey,nox

Fix immersive mode panic on three.js rollercoaster on hololens

We have some special logic about texture formats when creating drawing buffers for WebGL that needs to be shared with the code that creates a separate framebuffer for immersive mode.

---
- [x] `./mach build -d` does not report any errors
- [x] `./mach test-tidy` does not report any errors
- [x] These changes fix #24083 and fix #20595.
- [x] These changes do not require tests because no CI for hololens; tested manually in the emulator.

<!-- Reviewable:start -->
---
This change is [<img src="https://reviewable.io/review_button.svg" height="34" align="absmiddle" alt="Reviewable"/>](https://reviewable.io/reviews/servo/servo/24242)
<!-- Reviewable:end -->

tests/wpt/webgl/meta/conformance/extensions/oes-texture-half-float.html.ini

@@ -1,58 +1,24 @@
 [oes-texture-half-float.html]
-  [WebGL test #84: getError expected: INVALID_OPERATION. Was NO_ERROR : IMPLEMENTATION_COLOR_READ_TYPE should fail for incomplete framebuffers.]
+  [WebGL test #101: getError expected: NO_ERROR. Was INVALID_OPERATION : readPixels should return NO_ERROR when reading FLOAT data.]
     expected: FAIL
 
-  [WebGL test #97: getError expected: INVALID_FRAMEBUFFER_OPERATION. Was INVALID_OPERATION : readPixels should fail on incomplete framebuffers.]
+  [WebGL test #103: Green channel should be 0.25 for FLOAT readPixels. Received: 0]
     expected: FAIL
 
-  [WebGL test #89: gl.getParameter(gl.IMPLEMENTATION_COLOR_READ_TYPE) should be null (of type object). Was 5121 (of type number).]
+  [WebGL test #104: Blue channel should be 0.5 for FLOAT readPixels. Received: 0]
     expected: FAIL
 
-  [WebGL test #100: Green channel should be 0.25 for FLOAT readPixels. Received: 0]
+  [WebGL test #105: Alpha channel should be 0.75 for FLOAT readPixels. Received: 0]
     expected: FAIL
 
-  [WebGL test #91: getError expected: INVALID_FRAMEBUFFER_OPERATION. Was INVALID_OPERATION : readPixels should fail on incomplete framebuffers.]
+  [WebGL test #110: getError expected: NO_ERROR. Was INVALID_OPERATION : readPixels should return NO_ERROR when reading FLOAT data.]
     expected: FAIL
 
-  [WebGL test #88: getError expected: INVALID_OPERATION. Was NO_ERROR : IMPLEMENTATION_COLOR_READ_FORMAT should fail for incomplete framebuffers.]
+  [WebGL test #112: Green channel should be 0.25 for FLOAT readPixels. Received: 0]
     expected: FAIL
 
-  [WebGL test #90: getError expected: INVALID_OPERATION. Was NO_ERROR : IMPLEMENTATION_COLOR_READ_TYPE should fail for incomplete framebuffers.]
+  [WebGL test #113: Blue channel should be 0.5 for FLOAT readPixels. Received: 0]
     expected: FAIL
 
-  [WebGL test #95: gl.getParameter(gl.IMPLEMENTATION_COLOR_READ_TYPE) should be null (of type object). Was 5121 (of type number).]
+  [WebGL test #114: Alpha channel should be 1 for FLOAT readPixels. Received: 0]
     expected: FAIL
-
-  [WebGL test #85: getError expected: INVALID_FRAMEBUFFER_OPERATION. Was INVALID_OPERATION : readPixels should fail on incomplete framebuffers.]
-    expected: FAIL
-
-  [WebGL test #94: getError expected: INVALID_OPERATION. Was NO_ERROR : IMPLEMENTATION_COLOR_READ_FORMAT should fail for incomplete framebuffers.]
-    expected: FAIL
-
-  [WebGL test #101: Blue channel should be 0.5 for FLOAT readPixels. Received: 0]
-    expected: FAIL
-
-  [WebGL test #87: gl.getParameter(gl.IMPLEMENTATION_COLOR_READ_FORMAT) should be null (of type object). Was 6408 (of type number).]
-    expected: FAIL
-
-  [WebGL test #83: gl.getParameter(gl.IMPLEMENTATION_COLOR_READ_TYPE) should be null (of type object). Was 5121 (of type number).]
-    expected: FAIL
-
-  [WebGL test #81: gl.getParameter(gl.IMPLEMENTATION_COLOR_READ_FORMAT) should be null (of type object). Was 6408 (of type number).]
-    expected: FAIL
-
-  [WebGL test #98: getError expected: NO_ERROR. Was INVALID_OPERATION : readPixels should return NO_ERROR when reading FLOAT data.]
-    expected: FAIL
-
-  [WebGL test #102: Alpha channel should be 0.75 for FLOAT readPixels. Received: 0]
-    expected: FAIL
-
-  [WebGL test #93: gl.getParameter(gl.IMPLEMENTATION_COLOR_READ_FORMAT) should be null (of type object). Was 6408 (of type number).]
-    expected: FAIL
-
-  [WebGL test #96: getError expected: INVALID_OPERATION. Was NO_ERROR : IMPLEMENTATION_COLOR_READ_TYPE should fail for incomplete framebuffers.]
-    expected: FAIL
-
-  [WebGL test #82: getError expected: INVALID_OPERATION. Was NO_ERROR : IMPLEMENTATION_COLOR_READ_FORMAT should fail for incomplete framebuffers.]
-    expected: FAIL
-

tests/wpt/webgl/meta/conformance/textures/misc/copy-tex-image-2d-formats.html.ini

@@ -1,11 +0,0 @@
-[copy-tex-image-2d-formats.html]
-  bug: https://github.com/servo/servo/issues/20595
-  [WebGL test #32: getError expected: INVALID_OPERATION. Was NO_ERROR : should not be able to copyTexImage2D ALPHA from RGB]
-    expected: FAIL
-
-  [WebGL test #40: getError expected: INVALID_OPERATION. Was NO_ERROR : should not be able to copyTexImage2D RGBA from RGB]
-    expected: FAIL
-
-  [WebGL test #36: getError expected: INVALID_OPERATION. Was NO_ERROR : should not be able to copyTexImage2D LUMINANCE_ALPHA from RGB]
-    expected: FAIL
-

tests/wpt/webgl/meta/conformance/textures/misc/tex-input-validation.html.ini

@@ -6,9 +6,5 @@
   [WebGL test #61: getError expected: INVALID_OPERATION. Was NO_ERROR :  colorBufferFormat: RGB internalFormat: RGBA]
     expected: FAIL
 
-  [WebGL test #53: getError expected: INVALID_OPERATION. Was NO_ERROR :  colorBufferFormat: RGB internalFormat: RGBA]
+  [WebGL test #37: getError expected: NO_ERROR. Was INVALID_OPERATION :  colorBufferFormat: RGB565 internalFormat: RGB target: TEXTURE_2D border: 0]
     expected: FAIL
-
-  [WebGL test #34: getError expected: INVALID_OPERATION. Was NO_ERROR :  colorBufferFormat: RGB565 internalFormat: RGBA target: TEXTURE_2D border: 0]
-    expected: FAIL
-