Patch crash

For data gathering re SxS, apparently it's possible for Spotlight to
return a search query result for which there is no path. Defend
against this.

Bug: 1086555, 1061486
Change-Id: I972c6cda16d5c0801673addefd064cdfbc810904
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2218549
Auto-Submit: Avi Drissman <avi@chromium.org>
Commit-Queue: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772292}

chrome/browser/chrome_browser_main_mac.mm

@@ -114,6 +114,15 @@ void RecordChromeQueryResults(NSMetadataQuery* query) {
     // Filed as FB7689234.
     NSString* app_path = base::mac::ObjCCast<NSString>(
         [result valueForAttribute:NSMetadataItemPathKey]);
+    if (!app_path) {
+      // It seems implausible, but there are Macs in the field for which
+      // Spotlight will find results for the query of locating Chrome but cannot
+      // actually return a path to the result. https://crbug.com/1086555
+      failed_to_read_plist = true;
+      *stop = YES;
+      return;
+    }
+
     NSURL* app_url = [NSURL fileURLWithPath:app_path isDirectory:YES];
     if ([app_url isEqual:this_url])
       return;