Add data reduction functionality to all platforms.

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 6152d1305e3d9f39bcdddbafec574f2fe3903d94..bf9e7fec26e09e68ad0e5490a781b1d65ec1992f 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -307,6 +307,9 @@ class IOThread : public content::BrowserThreadDelegate {
   // well as the QUIC field trial group.
   void ConfigureQuic(const base::CommandLine& command_line);
 
+  // Set up data reduction proxy related objects on |IOThread::Globals|
+  void SetupDataReductionProxy(ChromeNetworkDelegate* network_delegate);

[Ryan Sleevi, 2014/07/22 01:56:30]

The Data Reduction Proxy is inherently privacy sensitive. I'm dismayed by the
fact that Incognito is being routed through it. This absolutely should not be
part of the IOThread Globals.

[Not at Google. Contact bengr, 2014/07/22 23:03:53]

We do not proxy incognito. We are making a change to make
DataReductionProxySettings a browser context keyed service that will not be
available for incognito. This will go away then. I can hold off on this cl until
that is done if you prefer.

+
   extensions::EventRouterForwarder* extension_event_router_forwarder() {
 #if defined(ENABLE_EXTENSIONS)
     return extension_event_router_forwarder_;