[PresentationService] Fix Start/Reconnect callback cleanup behavior.

When the NewPresentationCallbackWrapper is being destroyed, the
mojo callback is invoked to satisfy Mojo. This patch fixes the
PresentationError that it is invoked with to correctly reflect the
fact that the frame is being navigated or destroyed.

Note that this behavior is most likely invisible to the page anyway
since the page is going away when the callback is invoked.

Change-Id: If9428420727d5809f985fff8169fc9d8ed075703
Bug: 
Reviewed-on: https://chromium-review.googlesource.com/595348Reviewed-by: Takumi Fujimoto <takumif@chromium.org>
Commit-Queue: Derek Cheng <imcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491125}

content/browser/presentation/presentation_service_impl.cc

@@ -499,8 +499,12 @@ PresentationServiceImpl::NewPresentationCallbackWrapper::
 
 PresentationServiceImpl::NewPresentationCallbackWrapper::
     ~NewPresentationCallbackWrapper() {
-  if (!callback_.is_null())
-    InvokeNewPresentationCallbackWithError(std::move(callback_));
+  if (!callback_.is_null()) {
+    std::move(callback_).Run(
+        base::nullopt,
+        PresentationError(PRESENTATION_ERROR_PRESENTATION_REQUEST_CANCELLED,
+                          "The frame is navigating or being destroyed."));
+  }
 }
 
 void PresentationServiceImpl::NewPresentationCallbackWrapper::Run(