Remove excess spaces and reformat comment in spdy_session_pool.h.

This is a follow-up to https://crrev.com/c/1570914.

Bug: 912727
Change-Id: I284dbb580bb396da787c7d2f5755428458f88aeb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1577479Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Bence Béky <bnc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652866}

net/spdy/spdy_session_pool.h

@@ -207,13 +207,13 @@ class NET_EXPORT SpdySessionPool
   // another "blocking" request already pending. For example, the first request
   // created will be considered "blocking", but subsequent requests will not as
   // long as the "blocking" request is not destroyed.  Once the "blocking"
-  // request is destroyed, the next created request  will be marked "blocking".
+  // request is destroyed, the next created request will be marked "blocking".
   //
-  //  If a request is created, that request is not the "blocking" request, and
-  //  |on_blocking_request_destroyed_callback| is non-null,
-  // then |on_blocking_request_destroyed_callback| will be invoked
-  // asynchronously when the "blocking" request is destroyed. The callback
-  // associated with the "blocking" request is never invoked.
+  // If a request is created, that request is not the "blocking" request, and
+  // |on_blocking_request_destroyed_callback| is non-null, then
+  // |on_blocking_request_destroyed_callback| will be invoked asynchronously
+  // when the "blocking" request is destroyed. The callback associated with the
+  // "blocking" request is never invoked.
   //
   // |delegate|, |spdy_session_request|, and |is_blocking_request_for_session|
   // must all be non-null.