Add mechanism for global queueing and prioritization of DNS.

Currently this limit is very high (50), but it can be tuned through a variable.

BUG=9598
TEST=
HostResolverImplTest.HigherPriorityRequestsStartedFirst
HostResolverImplTest.CancelPendingRequest
HostResolverImplTest.QueueOverflow

Review URL: http://codereview.chromium.org/542086

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@37608 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 9 insertions, 1 deletions

diff --git a/net/base/host_resolver.h b/net/base/host_resolver.h
index 8a88402..0bcbbe8 100644
--- a/net/base/host_resolver.h
+++ b/net/base/host_resolver.h
@@ -11,6 +11,7 @@
 #include "googleurl/src/gurl.h"
 #include "net/base/address_family.h"
 #include "net/base/completion_callback.h"
+#include "net/base/request_priority.h"
 
 class MessageLoop;
 
@@ -40,7 +41,8 @@ class HostResolver : public base::RefCountedThreadSafe<HostResolver> {
           address_family_(ADDRESS_FAMILY_UNSPECIFIED),
           port_(port),
           allow_cached_response_(true),
-          is_speculative_(false) {}
+          is_speculative_(false),
+          priority_(MEDIUM) {}
 
     const int port() const { return port_; }
     const std::string& hostname() const { return hostname_; }
@@ -56,6 +58,9 @@ class HostResolver : public base::RefCountedThreadSafe<HostResolver> {
     bool is_speculative() const { return is_speculative_; }
     void set_is_speculative(bool b) { is_speculative_ = b; }
 
+    RequestPriority priority() const { return priority_; }
+    void set_priority(RequestPriority priority) { priority_ = priority; }
+
     const GURL& referrer() const { return referrer_; }
     void set_referrer(const GURL& referrer) { referrer_ = referrer; }
 
@@ -75,6 +80,9 @@ class HostResolver : public base::RefCountedThreadSafe<HostResolver> {
     // Whether this request was started by the DNS prefetcher.
     bool is_speculative_;
 
+    // The priority for the request.
+    RequestPriority priority_;
+
     // Optional data for consumption by observers. This is the URL of the
     // page that lead us to the navigation, for DNS prefetcher's benefit.
     GURL referrer_;