Make fewer connections in PacFileFetcherImplTest.IgnoresLimits.

It was making enough connections to exceed the total socket pool limit,
which is currently 256, and apparently large enough to cause timeouts on
some bots.  Switch to using the per-group limit instead - socket pool
tests themselves should make sure that ignore_limits ignores the global
pool limits as well, as there's no other way to exceed the per-group
limit, so just checking the per-group limit should be sufficient.

Bug: 820845
Change-Id: I2a661b535492c5bbca4e90710bd2d91e6115edfe
Reviewed-on: https://chromium-review.googlesource.com/964542
Commit-Queue: Matt Menke <mmenke@chromium.org>
Reviewed-by: Eric Roman <eroman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#544391}

net/proxy_resolution/pac_file_fetcher_impl_unittest.cc

@@ -540,13 +540,13 @@ TEST_F(PacFileFetcherImplTest, DataURLs) {
   }
 }
 
-// Makes sure that a request gets through when the socket pool is full, so
-// PacFileFetcherImpl can use the same URLRequestContext as everything else.
-TEST_F(PacFileFetcherImplTest, Priority) {
-  // Enough requests to exceed the per-pool limit, which is also enough to
-  // exceed the per-group limit.
-  int num_requests = 10 + ClientSocketPoolManager::max_sockets_per_pool(
-                              HttpNetworkSession::NORMAL_SOCKET_POOL);
+// Makes sure that a request gets through when the socket group for the PAC URL
+// is full, so PacFileFetcherImpl can use the same URLRequestContext as
+// everything else.
+TEST_F(PacFileFetcherImplTest, IgnoresLimits) {
+  // Enough requests to exceed the per-group limit.
+  int num_requests = 2 + ClientSocketPoolManager::max_sockets_per_group(
+                             HttpNetworkSession::NORMAL_SOCKET_POOL);
 
   net::test_server::SimpleConnectionListener connection_listener(
       num_requests, net::test_server::SimpleConnectionListener::