Add a command line flag to force all network traffic through a particular server.

The command line is:
  --fixed-server=host:port

When set, all traffic will be diverted through this server.  This is useful for
testing purposes with fixed servers.

BUG=none
TEST=none


Review URL: http://codereview.chromium.org/345034

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@30798 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 16 insertions, 5 deletions

diff --git a/chrome/browser/net/chrome_url_request_context.h b/chrome/browser/net/chrome_url_request_context.h
index 8bbfabe..5935297 100644
--- a/chrome/browser/net/chrome_url_request_context.h
+++ b/chrome/browser/net/chrome_url_request_context.h
@@ -33,7 +33,7 @@ class ChromeURLRequestContextFactory;
 // Most methods are expected to be called on the UI thread, except for
 // the destructor and GetURLRequestContext().
 class ChromeURLRequestContextGetter : public URLRequestContextGetter,
-                             public NotificationObserver {
+                                      public NotificationObserver {
  public:
   // Constructs a ChromeURLRequestContextGetter that will use |factory| to
   // create the ChromeURLRequestContext. If |profile| is non-NULL, then the
diff --git a/chrome/browser/net/dns_global.cc b/chrome/browser/net/dns_global.cc
index d70a3a0..7caef17 100644
--- a/chrome/browser/net/dns_global.cc
+++ b/chrome/browser/net/dns_global.cc
@@ -7,6 +7,7 @@
 #include <map>
 #include <string>
 
+#include "base/command_line.h"
 #include "base/singleton.h"
 #include "base/stats_counters.h"
 #include "base/string_util.h"
@@ -22,6 +23,7 @@
 #include "chrome/common/pref_names.h"
 #include "chrome/common/pref_service.h"
 #include "chrome/common/chrome_switches.h"
+#include "net/base/fixed_host_resolver.h"
 #include "net/base/host_resolver.h"
 #include "net/base/host_resolver_impl.h"
 
@@ -476,12 +478,21 @@ static void DiscardAllPrefetchState() {
 net::HostResolver* GetGlobalHostResolver() {
   // Called from UI thread.
   if (!global_host_resolver) {
+    const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+
+    // The FixedHostResolver allows us to send all network requests through
+    // a designated test server.
+    if (command_line.HasSwitch(switches::kFixedServer)) {
+      std::string host_and_port =
+          WideToASCII(command_line.GetSwitchValue(switches::kFixedServer));
+      global_host_resolver = new net::FixedHostResolver(host_and_port);
+      return global_host_resolver;
+    }
+
     global_host_resolver = net::CreateSystemHostResolver();
 
-    if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableIPv6)) {
-      global_host_resolver->SetDefaultAddressFamily(
-          net::ADDRESS_FAMILY_IPV4);
-    }
+    if (command_line.HasSwitch(switches::kDisableIPv6))
+      global_host_resolver->SetDefaultAddressFamily(net::ADDRESS_FAMILY_IPV4);
   }
   return global_host_resolver;
 }