Fix checks for GL_ETC1_RGB8_OES, disable it on D3D11.

src/libANGLE/renderer/d3d/d3d11/renderer11_utils.cpp

@@ -1585,6 +1585,11 @@ void GenerateCaps(ID3D11Device *device,
 
     // GL extension support
     extensions->setTextureExtensionSupport(*textureCapsMap);
+
+    // Explicitly disable GL_OES_compressed_ETC1_RGB8_texture because it's emulated and never
+    // becomes core. WebGL doesn't want to expose it unless there is native support.
+    extensions->compressedETC1RGB8Texture = false;
+
     extensions->elementIndexUint            = true;
     extensions->getProgramBinary            = true;
     extensions->rgb8rgba8                   = true;

src/libANGLE/renderer/gl/formatutilsgl.cpp

@@ -306,9 +306,9 @@ static InternalFormatInfoMap BuildInternalFormatInfoMap()
     // From GL_ANGLE_texture_compression_dxt5
     InsertFormatMapping(&map, GL_COMPRESSED_RGBA_S3TC_DXT5_ANGLE, ExtsOnly("GL_EXT_texture_compression_s3tc"),     AlwaysSupported(), NeverSupported(), ExtsOnly("GL_ANGLE_texture_compression_dxt5"), AlwaysSupported(), NeverSupported(),                      NeverSupported()                );
 
-    // From GL_ETC1_RGB8_OES
-    InsertFormatMapping(&map, GL_ETC1_RGB8_OES,                   VersionOrExts(4, 3, "GL_ARB_ES3_compatibility"), AlwaysSupported(), NeverSupported(), VersionOrExts(3, 0, "GL_ETC1_RGB8_OES"),       AlwaysSupported(), NeverSupported(),                      NeverSupported()                );
- 
+    // From GL_OES_compressed_ETC1_RGB8_texture
+    InsertFormatMapping(&map, GL_ETC1_RGB8_OES,                   VersionOrExts(4, 3, "GL_ARB_ES3_compatibility"), AlwaysSupported(), NeverSupported(), VersionOrExts(3, 0, "GL_OES_compressed_ETC1_RGB8_texture"),       AlwaysSupported(), NeverSupported(),                      NeverSupported()                );
+
     // From GL_OES_texture_compression_astc
     //                       | Format                                  | OpenGL texture   | Filter         | Render          | OpenGL ES texture support                      | Filter           | ES attachment   | ES renderbuffer |
     InsertFormatMapping(&map, GL_COMPRESSED_RGBA_ASTC_4x4_KHR,           NeverSupported(), NeverSupported(), NeverSupported(), ExtsOnly("GL_KHR_texture_compression_astc_ldr"), AlwaysSupported(), NeverSupported(), NeverSupported());