Fix Resource Priorities and Scheduling (Chrome Side)

content/browser/loader/resource_scheduler.h

Index: content/browser/loader/resource_scheduler.h
diff --git a/content/browser/loader/resource_scheduler.h b/content/browser/loader/resource_scheduler.h
index 60cf0cd69f8c10360b3c3f43babb2a61744e7443..7ed98ad00aca86e4b63ab156c7f061655c89f34e 100644
--- a/content/browser/loader/resource_scheduler.h
+++ b/content/browser/loader/resource_scheduler.h
@@ -165,6 +165,41 @@ class CONTENT_EXPORT ResourceScheduler : public base::NonThreadSafe {
     return outstanding_request_limit_;
   }
 
+  // Returns the priority level above which resources are considered
+  // layout-blocking if the html_body has not started.  It is also the threshold
+  // below which resources are considered delayable (and for completeness,
+  // a request that matches the threshold level is a high-priority but not
+  // layout-blocking request).

[mmenke, 2015/08/13 15:16:07]

That's actually not true - "in_flight_layout_blocking_threshold" is compared to
"non_delayable_requests_in_flight_count" rather than
"total_layout_blocking_count_".

[Pat Meenan, 2015/08/13 20:56:42]

Thanks - managed to confuse myself apparently.  Changed it to
in_flight_non_delayable because
enable_in_flight_layout_blocking_or_high_priority_threshold was just about
impossible to fit in 80 characters and it makes the comparison cleaner.

+  net::RequestPriority layout_blocking_or_high_priority_threshold() const {
+    return layout_blocking_or_high_priority_threshold_;
+  }
+
+  // Returns true if all delayable requests should be blocked while at least
+  // in_flight_layout_blocking_threshold() layout-blocking requests are
+  // in-flight during the layout-blocking phase of loading.
+  bool enable_in_flight_layout_blocking_threshold() const {
+    return enable_in_flight_layout_blocking_threshold_;
+  }
+
+  // Returns the number of in-flight layout-blocking requests above which
+  // all delayable requests should be blocked when
+  // enable_layout_blocking_threshold is set.
+  size_t in_flight_layout_blocking_threshold() const {
+    return in_flight_layout_blocking_threshold_;
+  }
+
+  // Returns the maximum number of delayable requests to allow be in-flight
+  // at any point in time while in the layout-blocking phase of loading.
+  size_t max_num_delayable_while_layout_blocking() const {
+    return max_num_delayable_while_layout_blocking_;
+  }
+
+  // Returns the maximum number of delayable requests to all be in-flight at
+  // any point in time (across all hosts).
+  size_t max_num_delayable_requests() const {
+    return max_num_delayable_requests_;
+  }
+
   enum ClientState {
     // Observable client.
     ACTIVE,
@@ -238,6 +273,11 @@ class CONTENT_EXPORT ResourceScheduler : public base::NonThreadSafe {
   size_t coalesced_clients_;
   bool limit_outstanding_requests_;
   size_t outstanding_request_limit_;
+  net::RequestPriority layout_blocking_or_high_priority_threshold_;
+  bool enable_in_flight_layout_blocking_threshold_;
+  size_t in_flight_layout_blocking_threshold_;
+  size_t max_num_delayable_while_layout_blocking_;
+  size_t max_num_delayable_requests_;
   // This is a repeating timer to initiate requests on COALESCED Clients.
   scoped_ptr<base::Timer> coalescing_timer_;
   RequestSet unowned_requests_;