Renderer-side changes for NoState Prefetch

chrome/renderer/prerender/prerender_helper.cc

Index: chrome/renderer/prerender/prerender_helper.cc
diff --git a/chrome/renderer/prerender/prerender_helper.cc b/chrome/renderer/prerender/prerender_helper.cc
index 2ea8d076cfdbce133dd32adc38bb1e0989b153b7..70f6637c8d45f478f4edafca01ca75ab0398989b 100644
--- a/chrome/renderer/prerender/prerender_helper.cc
+++ b/chrome/renderer/prerender/prerender_helper.cc
@@ -34,18 +34,39 @@ void UpdateVisibilityState(content::RenderFrame* render_frame) {
 
 namespace prerender {
 
-PrerenderHelper::PrerenderHelper(content::RenderFrame* render_frame)
+PrerenderHelper::PrerenderHelper(content::RenderFrame* render_frame,
+                                 PrerenderMode prerender_mode)
     : content::RenderFrameObserver(render_frame),
-      content::RenderFrameObserverTracker<PrerenderHelper>(render_frame) {
+      content::RenderFrameObserverTracker<PrerenderHelper>(render_frame),
+      prerender_mode_(prerender_mode) {
+  DCHECK_NE(prerender_mode_, NO_PRERENDER);
   UpdateVisibilityState(render_frame);
 }
 
+PrerenderHelper::PrerenderHelper(content::RenderFrame* sub_frame)
+    : PrerenderHelper(sub_frame,
+                      GetPrerenderMode(
+                          sub_frame->GetRenderView()->GetMainRenderFrame())) {
+  DCHECK(!render_frame()->IsMainFrame());
+}
+
 PrerenderHelper::~PrerenderHelper() {
 }
 
 // static.
 bool PrerenderHelper::IsPrerendering(const content::RenderFrame* render_frame) {
-  return PrerenderHelper::Get(render_frame) != NULL;
+  return PrerenderHelper::GetPrerenderMode(render_frame) != NO_PRERENDER;
+}
+
+// static.
+PrerenderMode PrerenderHelper::GetPrerenderMode(
+    const content::RenderFrame* render_frame) {
+  PrerenderHelper* helper = PrerenderHelper::Get(render_frame);
+  if (!helper)
+    return NO_PRERENDER;
+
+  DCHECK_NE(helper->prerender_mode_, NO_PRERENDER);
+  return helper->prerender_mode_;
 }
 
 bool PrerenderHelper::OnMessageReceived(