Don't require GL_ARB_gpu_shader5 in order to support ES 3.0.

src/compiler/translator/TranslatorGLSL.cpp

@@ -259,20 +259,14 @@ void TranslatorGLSL::writeExtensionBehavior(TIntermNode *root)
     }
 
     // Need to enable gpu_shader5 to have index constant sampler array indexing
-    if (getOutputType() != SH_ESSL_OUTPUT && getOutputType() < SH_GLSL_400_CORE_OUTPUT)
+    if (getOutputType() != SH_ESSL_OUTPUT && getOutputType() < SH_GLSL_400_CORE_OUTPUT &&
+        getShaderVersion() == 100)
     {
-        sink << "#extension GL_ARB_gpu_shader5 : ";
-
-        // Don't use "require" on WebGL 1 to avoid breaking WebGL on drivers that silently
-        // support index constant sampler array indexing, but don't have the extension.
-        if (getShaderVersion() >= 300)
-        {
-            sink << "require\n";
-        }
-        else
-        {
-            sink << "enable\n";
-        }
+        // Don't use "require" on to avoid breaking WebGL 1 on drivers that silently
+        // support index constant sampler array indexing, but don't have the extension or
+        // on drivers that don't have the extension at all as it would break WebGL 1 for
+        // some users.
+        sink << "#extension GL_ARB_gpu_shader5 : enable\n";
     }
 
     TExtensionGLSL extensionGLSL(getOutputType());

src/libANGLE/renderer/gl/renderergl_utils.cpp

@@ -549,16 +549,11 @@ void GenerateCaps(const FunctionsGL *functions, gl::Caps *caps, gl::TextureCapsM
         LimitVersion(maxSupportedESVersion, gl::Version(2, 0));
     }
 
-    // Check if index constant sampler array indexing is supported
-    if (!functions->isAtLeastGL(gl::Version(4, 0)) &&
-        !functions->isAtLeastGLES(gl::Version(2, 0)) &&
-        !functions->hasExtension("GL_ARB_gpu_shader5"))
-    {
-        // This should also be required for ES2 but there are some driver support index constant
-        // sampler array indexing without meeting the requirements above. Don't limit their ES
-        // version as it would break WebGL for some users.
-        LimitVersion(maxSupportedESVersion, gl::Version(2, 0));
-    }
+    // Non-constant sampler array indexing is required for OpenGL ES 2 and OpenGL ES after 3.2.
+    // However having it available on OpenGL ES 2 is a specification bug, and using this
+    // indexing in WebGL is undefined. Requiring this feature would break WebGL 1 for some users
+    // so we don't check for it. (it is present with ESSL 100, ESSL >= 320, GLSL >= 400 and
+    // GL_ARB_gpu_shader5)
 
     // Check if sampler objects are supported
     if (!functions->isAtLeastGL(gl::Version(3, 3)) &&