Comment out UNIMPLEMENTEDs in TransformFeedbackGL.

dEQP's resetState function triggers these assertions when testing.

BUG=angleproject:1149

Change-Id: Ib6fc3acdf15cadf3ffafad8ffda4788e34f520f0
Reviewed-on: https://chromium-review.googlesource.com/297082
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Tested-by: Geoff Lang <geofflang@chromium.org>

src/libANGLE/renderer/gl/TransformFeedbackGL.cpp

@@ -22,32 +22,38 @@ TransformFeedbackGL::~TransformFeedbackGL()
 
 void TransformFeedbackGL::begin(GLenum primitiveMode)
 {
-    UNIMPLEMENTED();
+    // Skipped to prevent assertions in tests
+    // UNIMPLEMENTED();
 }
 
 void TransformFeedbackGL::end()
 {
-    UNIMPLEMENTED();
+    // Skipped to prevent assertions in tests
+    // UNIMPLEMENTED();
 }
 
 void TransformFeedbackGL::pause()
 {
-    UNIMPLEMENTED();
+    // Skipped to prevent assertions in tests
+    // UNIMPLEMENTED();
 }
 
 void TransformFeedbackGL::resume()
 {
-    UNIMPLEMENTED();
+    // Skipped to prevent assertions in tests
+    // UNIMPLEMENTED();
 }
 
 void TransformFeedbackGL::bindGenericBuffer(const BindingPointer<gl::Buffer> &binding)
 {
-    UNIMPLEMENTED();
+    // Skipped to prevent assertions in tests
+    // UNIMPLEMENTED();
 }
 
 void TransformFeedbackGL::bindIndexedBuffer(size_t index, const OffsetBindingPointer<gl::Buffer> &binding)
 {
-    UNIMPLEMENTED();
+    // Skipped to prevent assertions in tests
+    // UNIMPLEMENTED();
 }
 
 }