Fix transform feedback bugs

gpu/command_buffer/client/gles2_implementation.cc

Index: gpu/command_buffer/client/gles2_implementation.cc
diff --git a/gpu/command_buffer/client/gles2_implementation.cc b/gpu/command_buffer/client/gles2_implementation.cc
index fc051b1fad3bfa6b1a9d2c61c2999cde84f192ee..e2c2d5f37334a684783bf95e93bd8bb9b142a970 100644
--- a/gpu/command_buffer/client/gles2_implementation.cc
+++ b/gpu/command_buffer/client/gles2_implementation.cc
@@ -3820,6 +3820,20 @@ void GLES2Implementation::BindBufferBaseHelper(
     GLenum target, GLuint index, GLuint buffer_id) {
   // TODO(zmo): See note #1 above.
   // TODO(zmo): See note #2 above.
+  switch (target) {

[Zhenyao Mo, 2016/03/02 17:09:36]

You will need to validate index before caching the binding.

[qiankun, 2016/03/03 10:14:15]

Done.

+    case GL_TRANSFORM_FEEDBACK_BUFFER:
+      if (bound_transform_feedback_buffer_ != buffer_id) {
+        bound_transform_feedback_buffer_ = buffer_id;
+      }
+      break;
+    case GL_UNIFORM_BUFFER:
+      if (bound_uniform_buffer_ != buffer_id) {
+        bound_uniform_buffer_ = buffer_id;
+      }
+      break;
+    default:
+      break;
+  }
   GetIdHandler(id_namespaces::kBuffers)->MarkAsUsedForBind(
       this, target, index, buffer_id, &GLES2Implementation::BindBufferBaseStub);
 }