Ignore RenderingCancelledException when logging errors in PDFRenderingQueue.renderView

Note that a `RenderingCancelledException` *should* never actually reach this method, but better safe than sorry I suppose, considering that both `PDFPageView` and `PDFThumbnailView` are already catching `RenderingCancelledException`s since those are *not* Errors in the normal sense of the word.

web/pdf_rendering_queue.js

@@ -13,6 +13,8 @@
  * limitations under the License.
  */
 
+import { RenderingCancelledException } from "pdfjs-lib";
+
 const CLEANUP_TIMEOUT = 30000;
 
 const RenderingStates = {
@@ -170,6 +172,9 @@ class PDFRenderingQueue {
             this.renderHighestPriority();
           })
           .catch(reason => {
+            if (reason instanceof RenderingCancelledException) {
+              return;
+            }
             console.error(`renderView: "${reason}"`);
           });
         break;