Offline pages : Fixed an unitialized variable

Fixed initialization of pending_state_ in SavePageRequest.

Bug: 844652
Change-Id: I8c4b2134dc74155330bc918be5e02e614610b2a9
Reviewed-on: https://chromium-review.googlesource.com/1066694Reviewed-by: Cathy Li <chili@chromium.org>
Commit-Queue: Shakti Sahu <shaktisahu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#560169}

components/offline_pages/core/background/save_page_request.cc

@@ -19,7 +19,8 @@ SavePageRequest::SavePageRequest(int64_t request_id,
       completed_attempt_count_(0),
       user_requested_(user_requested),
       state_(RequestState::AVAILABLE),
-      fail_state_(FailState::NO_FAILURE) {}
+      fail_state_(FailState::NO_FAILURE),
+      pending_state_(PendingState::NOT_PENDING) {}
 
 SavePageRequest::SavePageRequest(const SavePageRequest& other)
     : request_id_(other.request_id_),