Fix temporary directory leaks in the component updater unit tests.

Bug: 773049
Change-Id: Ib49946e9831e737e7ab65d5566b4601006a4bedf
Reviewed-on: https://chromium-review.googlesource.com/707593
Reviewed-by: Joshua Pawlicki <[email protected]>
Commit-Queue: Sorin Jianu <[email protected]>
Cr-Commit-Position: refs/heads/master@{#507527}
diff --git a/components/update_client/component.cc b/components/update_client/component.cc
index 864f957f..608b7ccd 100644
--- a/components/update_client/component.cc
+++ b/components/update_client/component.cc
@@ -506,6 +506,7 @@
   crx_downloader_.reset();
 
   if (download_result.error) {
+    DCHECK(download_result.response.empty());
     component.diff_error_category_ =
         static_cast<int>(ErrorCategory::kNetworkError);
     component.diff_error_code_ = download_result.error;
@@ -572,6 +573,7 @@
   crx_downloader_.reset();
 
   if (download_result.error) {
+    DCHECK(download_result.response.empty());
     component.error_category_ = static_cast<int>(ErrorCategory::kNetworkError);
     component.error_code_ = download_result.error;