Fix DCHECK failure in PrintRenderFrameHelper::PrintPreviewContext.

Accept the "DONE" state as a valid state for failing, since after the
rendering is done, there is still work to do and that work can
potentially fail.

BUG=872980

Change-Id: If1eb31c57057b2e6354dc4649ec7806468fa3f1d
Reviewed-on: https://chromium-review.googlesource.com/1170199Reviewed-by: Rebekah Potter <rbpotter@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#582775}

components/printing/renderer/print_render_frame_helper.cc

@@ -2306,7 +2306,7 @@ void PrintRenderFrameHelper::PrintPreviewContext::Finished() {
 }
 
 void PrintRenderFrameHelper::PrintPreviewContext::Failed(bool report_error) {
-  DCHECK(state_ == INITIALIZED || state_ == RENDERING);
+  DCHECK(state_ != UNINITIALIZED);
   state_ = INITIALIZED;
   if (report_error) {
     DCHECK_NE(PREVIEW_ERROR_NONE, error_);