[Merge m45] Fix possible reconcilor loop when the primary account is in an auth error state.

BUG=516070,529439
TBR=rogerta@chromium.org, nyquist@chromium.org

Review URL: https://codereview.chromium.org/1264143003

Cr-Commit-Position: refs/heads/master@{#348441}
(cherry picked from commit b32365ef9d9117c4b78cbee77361fd401e8841a2)

Review URL: https://codereview.chromium.org/1336393002 .

Cr-Commit-Position: refs/branch-heads/2454@{#472}
Cr-Branched-From: 12bfc3360892ec53cd00fc239a47e5298beb063b-refs/heads/master@{#338390}

diff --git a/components/signin/core/browser/gaia_cookie_manager_service.cc b/components/signin/core/browser/gaia_cookie_manager_service.cc
index 4beff36..607c2a2 100644
--- a/components/signin/core/browser/gaia_cookie_manager_service.cc
+++ b/components/signin/core/browser/gaia_cookie_manager_service.cc

@@ -427,40 +427,22 @@
   fetcher_timer_.Stop();
 }
 
-// It is unknown if the cookie was changed because of processing initiated by
-// this class or other (such as the user clearing all cookies or a cookie being
-// evicted).
 void GaiaCookieManagerService::OnCookieChanged(
     const net::CanonicalCookie& cookie,
     bool removed) {
   DCHECK_EQ("APISID", cookie.Name());
   DCHECK_EQ(GaiaUrls::GetInstance()->google_url().host(), cookie.Domain());
+  // Ignore changes to the cookie while requests are pending.  These changes
+  // are caused by the service itself as it adds accounts.  A side effects is
+  // that any changes to the gaia cookie outside of this class, while requests
+  // are pending, will be lost.  However, trying to process these changes could
+  // cause an endless loop (see crbug.com/516070).
   if (requests_.empty()) {
     requests_.push_back(GaiaCookieRequest::CreateListAccountsRequest());
     fetcher_retries_ = 0;
     signin_client_->DelayNetworkCall(
         base::Bind(&GaiaCookieManagerService::StartFetchingListAccounts,
                    base::Unretained(this)));
-  } else {
-    // Remove all pending ListAccount calls; for efficiency, only call
-    // after all pending requests are processed.
-    // Track requests to keep; all other unstarted requests will be removed.
-    std::vector<GaiaCookieRequest> requests_to_keep;
-
-    // Check all pending, non-executing requests.
-    for (auto it = requests_.begin() + 1; it != requests_.end(); ++it) {
-      // Keep all requests except for LIST_ACCOUNTS.
-      if (it->request_type() != GaiaCookieRequestType::LIST_ACCOUNTS)
-        requests_to_keep.push_back(*it);
-    }
-
-    // Remove all but the executing request. Re-add all requests being kept.
-    if (requests_.size() > 1) {
-      requests_.erase(requests_.begin() + 1, requests_.end());
-      requests_.insert(
-          requests_.end(), requests_to_keep.begin(), requests_to_keep.end());
-    }
-    requests_.push_back(GaiaCookieRequest::CreateListAccountsRequest());
   }
 }