Migrate components/data_reduction_proxy to Mojo interfaces.

chrome/browser/chrome_content_browser_client.cc

Index: chrome/browser/chrome_content_browser_client.cc
diff --git a/chrome/browser/chrome_content_browser_client.cc b/chrome/browser/chrome_content_browser_client.cc
index 710f5b5b500e9523f2147f14b1cb323231912f7e..4cd6d5efc467f990c0e3907969ab0846dda15080 100644
--- a/chrome/browser/chrome_content_browser_client.cc
+++ b/chrome/browser/chrome_content_browser_client.cc
@@ -117,7 +117,7 @@
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings.h"
 #include "components/content_settings/core/common/content_settings_types.h"
-#include "components/data_reduction_proxy/content/browser/data_reduction_proxy_message_filter.h"
+#include "components/data_reduction_proxy/content/browser/data_reduction_proxy_host_impl.h"
 #include "components/dom_distiller/core/dom_distiller_switches.h"
 #include "components/dom_distiller/core/url_constants.h"
 #include "components/error_page/common/error_page_switches.h"
@@ -991,8 +991,10 @@ void ChromeContentBrowserClient::RenderProcessWillLaunch(
 #endif
   DataReductionProxyChromeSettings* data_reduction_proxy_settings =
       DataReductionProxyChromeSettingsFactory::GetForBrowserContext(profile);
-  host->AddFilter(new data_reduction_proxy::DataReductionProxyMessageFilter(
-      data_reduction_proxy_settings));
+  host->GetServiceRegistry()->AddService(

[leonhsl(Using Gerrit), 2016/06/14 10:16:48]

Instead of here I think it's better to put the AddService call into
ChromeContentBrowserClient::RegisterRenderProcessMojoServices(service_registry),
but there we can't get the target RPH, which is necessary to get the attached
DataReductionProxyChromeSettings instance.
So how about we add one more parameter(the RPH) to the original function
declaration, just as:
ContentBrowserClient::RegisterRenderProcessMojoServices(service_registry,
render_process_host)? This way will enable bind some RPH-specific information.
WDYT?

[Anand Mistry (off Chromium), 2016/06/15 08:09:40]

I think that's reasonable given that the RenderFrameHost equivalent provides the
host. I suggest doing it as a separate CL since it's orthogonal to this one and
likely to be reviewed faster.

[leonhsl(Using Gerrit), 2016/06/16 08:28:30]

Done.
A separate CL https://codereview.chromium.org/2060943005/ has been landed and
for this CL moved AddService call into
ChromeContentBrowserClient::RegisterRenderProcessMojoServices(). Thanks! 

+      base::Bind(&data_reduction_proxy::DataReductionProxyHostImpl::Create,
+                 data_reduction_proxy_settings),
+      BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
 
   host->GetImmediateSender()->Send(new ChromeViewMsg_SetIsIncognitoProcess(
       profile->IsOffTheRecord()));