Added Client-Hints.

chrome/browser/net/chrome_network_delegate.cc

Index: chrome/browser/net/chrome_network_delegate.cc
diff --git a/chrome/browser/net/chrome_network_delegate.cc b/chrome/browser/net/chrome_network_delegate.cc
index c66e5152256f6a459361aa82a614900d8c6dd0f6..333e08264bd3db9c3d47f74fad642f9f838066f2 100644
--- a/chrome/browser/net/chrome_network_delegate.cc
+++ b/chrome/browser/net/chrome_network_delegate.cc
@@ -24,6 +24,7 @@
 #include "chrome/browser/extensions/extension_process_manager.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/google/google_util.h"
+#include "chrome/browser/net/client_hints.h"
 #include "chrome/browser/net/connect_interceptor.h"
 #include "chrome/browser/net/load_time_stats.h"
 #include "chrome/browser/performance_monitor/performance_monitor.h"
@@ -75,6 +76,7 @@ bool ChromeNetworkDelegate::g_never_throttle_requests_ = false;
 namespace {
 
 const char kDNTHeader[] = "DNT";
+const char kClientHintsHeader[] = "Client-Hints";
 
 // If the |request| failed due to problems with a proxy, forward the error to
 // the proxy extension API.
@@ -279,6 +281,7 @@ ChromeNetworkDelegate::ChromeNetworkDelegate(
       original_content_length_(0) {
   DCHECK(event_router);
   DCHECK(enable_referrers);
+  client_hints_ = ClientHints::create();

[Ryan Sleevi, 2013/01/16 23:19:56]

Why a static method? Why not new ClientHints?

[bengr (incorrect), 2013/01/17 01:50:44]

Done.

 }
 
 ChromeNetworkDelegate::~ChromeNetworkDelegate() {}
@@ -383,6 +386,23 @@ int ChromeNetworkDelegate::OnBeforeURLRequest(
   if (enable_do_not_track_ && enable_do_not_track_->GetValue())
     request->SetExtraRequestHeaderByName(kDNTHeader, "1", true /* override */);
 
+  // TODO(bengr): Put behind experimental flag.
+  int process_id, render_view_id;
+  const ResourceRequestInfo* info = ResourceRequestInfo::ForRequest(request);
+  if (info && info->GetAssociatedRenderView(&process_id, &render_view_id)) {
+    if (client_hints_->IsScreenInfoAvailable(process_id, render_view_id)) {
+      std::string client_hints_value =
+          client_hints_->GetScreenInfoHints(process_id, render_view_id);
+      request->SetExtraRequestHeaderByName(kClientHintsHeader,
+                                           client_hints_value, true);
+      DVLOG(2) << kClientHintsHeader << ": " << client_hints_value
+          << " for " << request->url().spec();
+    } else {
+      DVLOG(2) << kClientHintsHeader << " not available for "
+          << request->url().spec();
+    }
+  }
+
   bool force_safe_search = force_google_safe_search_ &&
                            force_google_safe_search_->GetValue();