Set more ANGLE shader translation properties for WebGL 2

[jdm]

Fixes #25034.

[highfive]

Heads up! This PR modifies the following files:

• @asajeffrey: components/script/dom/webglshader.rs
• @KiChjang: components/script/dom/webglshader.rs

[highfive]

Warning

• These commits modify script code, but no tests are modified. Please consider adding a test!

[jdm]

@bors-servo try=wpt

[bors-servo]

⌛ Trying commit b5911a4 with merge fdffa80...

[bors-servo]

💔 Test failed - status-taskcluster

[asajeffrey]

Some nits but mostly LGTM.

[jdm]

  ▶ CRASH [expected ERROR] /_webgl/conformance2/uniforms/incompatible-texture-type-for-sampler.html
  │ 
  │ 
  │ 
  │ 
  │ [2019-12-19T22:21:01Z ERROR canvas::webgl_thread] Last GL operation failed: TexImage2D { target: 3553, level: 0, effective_internal_format: 6406, size: 1×1, format: Alpha, data_type: UnsignedByte, effective_data_type: 5121, unpacking_alignment: 4, alpha_treatment: None, y_axis_treatment: AsIs, pixel_format: None, data: IpcSharedMemory { os... }
  │ Unexpected WebGL error: 0x501 (1281) [TexImage2D { target: 3553, level: 0, effective_internal_format: 6406, size: 1×1, format: Alpha, data_type: UnsignedByte, effective_data_type: 5121, unpacking_alignment: 4, alpha_treatment: None, y_axis_treatment: AsIs, pixel_format: None, data: IpcSharedMemory { os... }] (thread WebGL thread, at components/canvas/webgl_thread.rs:1819)
 
  ▶ ERROR [expected OK] /_webgl/conformance2/programs/gl-get-frag-data-location.html
  │   → gl.getFragDataLocation is not a function
  │ 
  │ runTests@http://web-platform.test:8000/_webgl/conformance2/programs/gl-get-frag-data-location.html:95:17
  └ @http://web-platform.test:8000/_webgl/conformance2/programs/gl-get-frag-data-location.html:83:3
  ▶ Unexpected subtest result in /_webgl/conformance2/programs/gl-get-frag-data-location.html:
  │ FAIL [expected PASS] WebGL test #2: successfullyParsed should be true (of type boolean). Was undefined (of type undefined).
  │   → assert_true: successfullyParsed should be true (of type boolean). Was undefined (of type undefined). expected true got false
  │ 
  │ reportTestResultsToHarness/<@http://web-platform.test:8000/_webgl/js/js-test-pre.js:123:9
  │ Test.prototype.step@http://web-platform.test:8000/resources/testharness.js:1984:25
  │ test@http://web-platform.test:8000/resources/testharness.js:548:30
  │ reportTestResultsToHarness@http://web-platform.test:8000/_webgl/js/js-test-pre.js:122:7
  │ testFailed@http://web-platform.test:8000/_webgl/js/js-test-pre.js:249:5
  │ shouldBe@http://web-platform.test:8000/_webgl/js/js-test-pre.js:406:9
  │ shouldBeTrue@http://web-platform.test:8000/_webgl/js/js-test-pre.js:432:29
  └ @http://web-platform.test:8000/_webgl/js/js-test-post.js:24:1

[jdm]

The gl-get-frag-data-location.html is new because the test previously returned early when the compiling the program failed. Now that it doesn't, we hit different errors.

The new GL error is almost certainly caused by disabling the compat mode, since it's using ALPHA.

[asajeffrey]

Oh good, compat mode again.

[jdm]

@bors-servo r=asajeffrey

[bors-servo]

📌 Commit 156ad64 has been approved by asajeffrey

[bors-servo]

⌛ Testing commit 156ad64 with merge 64f5a93...

[bors-servo]

💔 Test failed - status-taskcluster

[jdm]

@bors-servo retry

• #25459

[bors-servo]

⌛ Testing commit 156ad64 with merge 3f5cb0e...

[bors-servo]

☀️ Test successful - status-taskcluster
Approved by: asajeffrey
Pushing 3f5cb0e to master...