[Impeller] Do not skip the GLES render pass if the command list is em…

…pty (#50381)

The render pass may need to apply other changes such as painting the clear color.

See flutter/flutter#142639

impeller/renderer/backend/gles/render_pass_gles.cc

@@ -151,10 +151,6 @@ struct RenderPassData {
     const std::shared_ptr<GPUTracerGLES>& tracer) {
   TRACE_EVENT0("impeller", "RenderPassGLES::EncodeCommandsInReactor");
 
-  if (commands.empty()) {
-    return true;
-  }
-
   const auto& gl = reactor.GetProcTable();
 #ifdef IMPELLER_DEBUG
   tracer->MarkFrameStart(gl);
@@ -517,9 +513,6 @@ bool RenderPassGLES::OnEncodeCommands(const Context& context) const {
   if (!IsValid()) {
     return false;
   }
-  if (commands_.empty()) {
-    return true;
-  }
   const auto& render_target = GetRenderTarget();
   if (!render_target.HasColorAttachment(0u)) {
     return false;