Add enough ES 3.1 enums to support initializing the dEQP ES 3.1 tests.

BUG=angleproject:1442

Change-Id: Iece3efb272fdcbe004d4136129ba7bfe74ba5265
Reviewed-on: https://chromium-review.googlesource.com/405530
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/Context.cpp b/src/libANGLE/Context.cpp
index 86f68c9..0be5491 100644
--- a/src/libANGLE/Context.cpp
+++ b/src/libANGLE/Context.cpp
@@ -306,6 +306,12 @@
         Texture *zeroTexture2DArray = new Texture(mImplementation.get(), 0, GL_TEXTURE_2D_ARRAY);
         mZeroTextures[GL_TEXTURE_2D_ARRAY].set(zeroTexture2DArray);
     }
+    if (getClientVersion() >= Version(3, 1))
+    {
+        Texture *zeroTexture2DMultisample =
+            new Texture(mImplementation.get(), 0, GL_TEXTURE_2D_MULTISAMPLE);
+        mZeroTextures[GL_TEXTURE_2D_MULTISAMPLE].set(zeroTexture2DMultisample);
+    }
 
     if (mExtensions.eglImageExternal || mExtensions.eglStreamConsumerExternal)
     {
@@ -3562,6 +3568,18 @@
         case GL_TRANSFORM_FEEDBACK_BUFFER:
             bindGenericTransformFeedbackBuffer(buffer);
             break;
+        case GL_ATOMIC_COUNTER_BUFFER:
+            UNIMPLEMENTED();
+            break;
+        case GL_SHADER_STORAGE_BUFFER:
+            UNIMPLEMENTED();
+            break;
+        case GL_DRAW_INDIRECT_BUFFER:
+            UNIMPLEMENTED();
+            break;
+        case GL_DISPATCH_INDIRECT_BUFFER:
+            UNIMPLEMENTED();
+            break;
 
         default:
             UNREACHABLE();