Convert network hints to Mojo

components/network_hints/renderer/renderer_dns_prefetch.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // A RendererDnsPrefetch instance is maintained for each RenderThread.
 // URL strings are typically added to the embedded queue during rendering.
 // The first addition to the queue (transitioning from empty to having
 // some names) causes a processing task to be added to the Renderer Thread.
 // The processing task gathers all buffered names, and send them via IPC
 // to the browser, so that DNS lookups can be performed before the user attempts
@@ skipping 10 matching lines @@
 #ifndef COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_DNS_PREFETCH_H_
 #define COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_DNS_PREFETCH_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
+#include "components/network_hints/common/network_hints.mojom.h"
 #include "components/network_hints/renderer/dns_prefetch_queue.h"
 
 namespace network_hints {
 
+class NetworkHints;
+
 // An internal interface to the network_hints component for efficiently sending
 // DNS prefetch requests to the net stack.
 class RendererDnsPrefetch {
  public:
   RendererDnsPrefetch();
   ~RendererDnsPrefetch();
 
   // Push a name into the queue to be resolved.
   void Resolve(const char* name, size_t length);
 
@@ skipping 25 matching lines @@
   // DnsPrefetchNames does not check the buffer, and just sends names
   // that are already collected in the domain_map_ for DNS lookup.
   // If max_count is zero, then all available names are sent; and
   // if positive, then at most max_count names will be sent.
   void DnsPrefetchNames(size_t max_count = 0);
 
   // Reset() restores initial state provided after construction.
   // This discards ALL queue entries, and map entries.
   void Reset();
 
+  // Ensure that the Mojo connection to NetworkHints has been created.
+  void EnsureConnected();

[Sam McNally, 2016/07/12 05:25:30]

I would prefer a getter that returns a mojom::NetworkHints& that connects if
necessary.

[tibell, 2016/07/12 07:14:24]

Done.

+
   // We use c_string_queue_ to hold lists of names supplied typically) by the
   // renderer.  It queues the names, at minimal cost to the renderer's thread,
   // and allows this class to process them when time permits (in a later task).
   DnsQueue c_string_queue_;
 
 
   // domain_map_ contains (for each domain) one of the next two constants,
   // depending on whether we have asked the browser process to do the actual
   // DNS lookup.
   static const int kLookupRequested = 0x1;
   static const int kPending = 0x0;
   typedef std::map<std::string, int> DomainUseMap;
   DomainUseMap domain_map_;
 
   // Cache a tally of the count of names that haven't yet been sent
   // for DNS pre-fetching.  Note that we *could* recalculate this
   // count by iterating over domain_map_, looking for even values.
   size_t new_name_count_;
 
   // We have some metrics to examine performance.  We might use
   // these metrics to modify buffer counts etc. some day.
   int buffer_full_discard_count_;
   int numeric_ip_discard_count_;
 
+  // |EnsureConnected()| must be called before sending messages using
+  // |network_hints_|.
+  mojom::NetworkHintsPtr network_hints_;
+
   base::WeakPtrFactory<RendererDnsPrefetch> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererDnsPrefetch);
 };  // class RendererDnsPrefetch
 
 }  // namespace network_hints
 
 #endif  // COMPONENTS_NETWORK_HINTS_RENDERER_RENDERER_DNS_PREFETCH_H_