Implement WebPrescientNetworking to trigger preconnect from Blink

chrome/common/render_messages.h

Index: chrome/common/render_messages.h
diff --git a/chrome/common/render_messages.h b/chrome/common/render_messages.h
index 4c1876d2b7891e7fa6d9beced238ed1c5058d186..790dd57e2c0f63270ea321ac6b0b48563a4189bf 100644
--- a/chrome/common/render_messages.h
+++ b/chrome/common/render_messages.h
@@ -32,6 +32,7 @@
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebCache.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebConsoleMessage.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebPreconnectMotivation.h"
 #include "ui/base/window_open_disposition.h"
 #include "ui/gfx/rect.h"
 
@@ -126,6 +127,7 @@ IPC_ENUM_TRAITS(ThemeBackgroundImageAlignment)
 IPC_ENUM_TRAITS(ThemeBackgroundImageTiling)
 IPC_ENUM_TRAITS(TranslateErrors::Type)
 IPC_ENUM_TRAITS(WebKit::WebConsoleMessage::Level)
+IPC_ENUM_TRAITS(WebKit::WebPreconnectMotivation)
 
 IPC_STRUCT_TRAITS_BEGIN(ChromeViewHostMsg_GetPluginInfo_Status)
 IPC_STRUCT_TRAITS_MEMBER(value)
@@ -615,6 +617,12 @@ IPC_MESSAGE_CONTROL2(ChromeViewHostMsg_V8HeapStats,
 IPC_MESSAGE_CONTROL1(ChromeViewHostMsg_DnsPrefetch,
                      std::vector<std::string> /* hostnames */)
 
+// Request for preconnect to host providing resource specified by URL
+IPC_MESSAGE_CONTROL3(ChromeViewHostMsg_Preconnect,
+                     GURL /* preconnect target url */,
+                     WebKit::WebPreconnectMotivation,
+                     uint32_t /* motivationVariationId */)
+
 // Notifies when a plugin couldn't be loaded because it's outdated.
 IPC_MESSAGE_ROUTED2(ChromeViewHostMsg_BlockedOutdatedPlugin,
                     int /* placeholder ID */,