Check if mojo pipe is bound before binding speech recognition context

This CL adds a check to prevent binding the speech recognition context
if the mojo pipe to the speech recognition service is not bound. This
can occur if the Speech On-Device API (SODA) files were not found.

Bug: 1147226
Change-Id: I86fe0a4b9fe80de0449e196b451423cbcf2b8a60
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2538054Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Evan Liu <evliu@google.com>
Cr-Commit-Position: refs/heads/master@{#827427}

chrome/browser/speech/speech_recognition_service.cc

@@ -32,7 +32,9 @@ SpeechRecognitionService::~SpeechRecognitionService() = default;
 void SpeechRecognitionService::Create(
     mojo::PendingReceiver<media::mojom::SpeechRecognitionContext> receiver) {
   LaunchIfNotRunning();
-  speech_recognition_service_->BindContext(std::move(receiver));
+
+  if (speech_recognition_service_.is_bound())
+    speech_recognition_service_->BindContext(std::move(receiver));
 }
 
 void SpeechRecognitionService::OnNetworkServiceDisconnect() {