PlzNavigate: support NavigationThrottle::WillProcessResponse

content/renderer/render_frame_impl.cc

Index: content/renderer/render_frame_impl.cc
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index a41cdb260b8e4372543204bdd996cae5d36ee182..0b391f466454673862587a101d3bbc44074e755a 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -1422,6 +1422,7 @@ bool RenderFrameImpl::OnMessageReceived(const IPC::Message& msg) {
     IPC_MESSAGE_HANDLER(FrameMsg_SerializeAsMHTML, OnSerializeAsMHTML)
     IPC_MESSAGE_HANDLER(FrameMsg_Find, OnFind)
     IPC_MESSAGE_HANDLER(FrameMsg_StopFinding, OnStopFinding)
+    IPC_MESSAGE_HANDLER(FrameMsg_EnableViewSourceMode, OnEnableViewSourceMode)
 #if defined(OS_ANDROID)
     IPC_MESSAGE_HANDLER(InputMsg_ActivateNearestFindResult,
                         OnActivateNearestFindResult)
@@ -5088,6 +5089,13 @@ void RenderFrameImpl::OnStopFinding(StopFindAction action) {
   }
 }
 
+void RenderFrameImpl::OnEnableViewSourceMode() {
+  if (!frame_)
+    return;
+  DCHECK(!frame_->parent());
+  frame_->enableViewSourceMode(true);
+}
+
 #if defined(OS_ANDROID)
 void RenderFrameImpl::OnActivateNearestFindResult(int request_id,
                                                   float x,