Migrate components/data_reduction_proxy to Mojo interfaces.

chrome/renderer/page_load_histograms.cc

Index: chrome/renderer/page_load_histograms.cc
diff --git a/chrome/renderer/page_load_histograms.cc b/chrome/renderer/page_load_histograms.cc
index 77c988690b08e85e244e447b3c9cc61edfdac46c..8f27f37a894672c07f628d5cf41b1d0e8788833b 100644
--- a/chrome/renderer/page_load_histograms.cc
+++ b/chrome/renderer/page_load_histograms.cc
@@ -21,7 +21,7 @@
 #include "base/time/time.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/renderer/searchbox/search_bouncer.h"
-#include "components/data_reduction_proxy/content/common/data_reduction_proxy_messages.h"
+#include "components/data_reduction_proxy/content/common/data_reduction_proxy.mojom.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
 #include "content/public/common/content_constants.h"
 #include "content/public/renderer/document_state.h"
@@ -31,6 +31,7 @@
 #include "extensions/common/url_pattern.h"
 #include "net/base/url_util.h"
 #include "net/http/http_response_headers.h"
+#include "services/shell/public/cpp/interface_provider.h"
 #include "third_party/WebKit/public/platform/URLConversion.h"
 #include "third_party/WebKit/public/platform/WebURLRequest.h"
 #include "third_party/WebKit/public/platform/WebURLResponse.h"
@@ -887,9 +888,12 @@ void PageLoadHistograms::Dump(WebFrame* frame) {
 
   bool data_reduction_proxy_was_used = false;
   if (!document_state->proxy_server().IsEmpty()) {
-    bool handled =
-        Send(new DataReductionProxyViewHostMsg_IsDataReductionProxy(
-            document_state->proxy_server(), &data_reduction_proxy_was_used));
+    data_reduction_proxy::mojom::DataReductionProxyHostPtr
+        data_reduction_proxy_host;
+    content::RenderThread::Get()->GetRemoteInterfaces()->GetInterface(
+        mojo::GetProxy(&data_reduction_proxy_host));
+    bool handled = data_reduction_proxy_host->IsDataReductionProxy(

[dcheng, 2016/07/08 05:50:53]

How expensive is it to create / tear down a message pipe everytime we query this
state? It definitely seems less efficient than legacy IPC, since we'd just route
one message there.

[leonhsl(Using Gerrit), 2016/07/11 14:36:07]

From my understanding this call will just happen once for each main render
frame, and as I remember that a mojo message pipe should be cheap to create and
destroy, so I made this choice. I referenced some other mojofication works which
are also using mojo message pipes as if it's free ;-)

+        document_state->proxy_server(), &data_reduction_proxy_was_used);
     // If the IPC call is not handled, then |data_reduction_proxy_was_used|
     // should remain |false|.
     DCHECK(handled || !data_reduction_proxy_was_used);