Do not propagate OVR_multiview extension directive

src/compiler/translator/TranslatorESSL.cpp

@@ -120,6 +120,10 @@ void TranslatorESSL::writeExtensionBehavior(ShCompileOptions compileOptions)
 {
     TInfoSinkBase &sink                   = getInfoSink().obj;
     const TExtensionBehavior &extBehavior = getExtensionBehavior();
+    const bool isMultiviewExtEmulated =
+        (compileOptions & (SH_TRANSLATE_VIEWID_OVR_TO_UNIFORM |
+                           SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW)) != 0u;
+
     for (TExtensionBehavior::const_iterator iter = extBehavior.begin(); iter != extBehavior.end();
          ++iter)
     {
@@ -136,7 +140,7 @@ void TranslatorESSL::writeExtensionBehavior(ShCompileOptions compileOptions)
                 sink << "#extension GL_NV_draw_buffers : " << getBehaviorString(iter->second)
                      << "\n";
             }
-            else if (compileOptions & SH_TRANSLATE_VIEWID_OVR_TO_UNIFORM &&
+            else if (isMultiviewExtEmulated &&
                      (iter->first == "GL_OVR_multiview" || iter->first == "GL_OVR_multiview2"))
             {
                 // No output

src/tests/compiler_tests/WEBGL_multiview_test.cpp

@@ -690,4 +690,30 @@ TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, ViewIDAndInstanceIDHaveCorrectV
 
     EXPECT_TRUE(foundInHLSLCode("ViewID_OVR = (uvec1(gl_InstanceID) % 3)"));
     EXPECT_TRUE(foundInHLSLCode("InstanceID = (gl_InstanceID / 3)"));
-}
\ No newline at end of file
+}
+
+// The test checks that the directive enabling GL_OVR_multiview is not outputted if the extension is
+// emulated.
+TEST_F(WEBGLMultiviewVertexShaderOutputCodeTest, StrippedOVRMultiviewDirective)
+{
+    const std::string &shaderString =
+        "#version 300 es\n"
+        "#extension GL_OVR_multiview : require\n"
+        "layout(num_views = 3) in;\n"
+        "void main()\n"
+        "{\n"
+        "}\n";
+    // The directive must not be present if any of the multiview emulation options are set.
+    compile(shaderString, SH_INITIALIZE_BUILTINS_FOR_INSTANCED_MULTIVIEW);
+    EXPECT_FALSE(foundInESSLCode("GL_OVR_multiview"));
+    EXPECT_FALSE(foundInGLSLCode("GL_OVR_multiview"));
+
+    compile(shaderString, SH_TRANSLATE_VIEWID_OVR_TO_UNIFORM);
+    EXPECT_FALSE(foundInESSLCode("GL_OVR_multiview"));
+    EXPECT_FALSE(foundInGLSLCode("GL_OVR_multiview"));
+
+    // The directive should be outputted from the ESSL translator with none of the options being
+    // set.
+    compile(shaderString);
+    EXPECT_TRUE(foundInESSLCode("GL_OVR_multiview"));
+}