Add chromium side implementation of WebKit::WebCrypto.

content/renderer/renderer_webkitplatformsupport_impl.cc

Index: content/renderer/renderer_webkitplatformsupport_impl.cc
diff --git a/content/renderer/renderer_webkitplatformsupport_impl.cc b/content/renderer/renderer_webkitplatformsupport_impl.cc
index c5db18644d6a3fbdff104428201b001a4c6014c6..ede8473e8d7684b5c7747b66232c311f0f00764d 100644
--- a/content/renderer/renderer_webkitplatformsupport_impl.cc
+++ b/content/renderer/renderer_webkitplatformsupport_impl.cc
@@ -40,6 +40,7 @@
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/renderer_clipboard_client.h"
 #include "content/renderer/webclipboard_impl.h"
+#include "content/renderer/webcrypto_impl.h"
 #include "content/renderer/websharedworkerrepository_impl.h"
 #include "gpu/config/gpu_info.h"
 #include "ipc/ipc_sync_message_filter.h"
@@ -1072,4 +1073,13 @@ void RendererWebKitPlatformSupportImpl::setDeviceMotionListener(
   device_motion_event_pump_->SetListener(listener);
 }
 
+//------------------------------------------------------------------------------
+
+WebKit::WebCrypto* RendererWebKitPlatformSupportImpl::crypto() {
+  if (!web_crypto_)
+    web_crypto_.reset(new WebCryptoImpl());
+  return web_crypto_.get();
+
+}
+
 }  // namespace content