[NoStatePrefetch] Do not send responses to renderer in prefetch mode.

third_party/WebKit/Source/web/WebDocument.cpp

Index: third_party/WebKit/Source/web/WebDocument.cpp
diff --git a/third_party/WebKit/Source/web/WebDocument.cpp b/third_party/WebKit/Source/web/WebDocument.cpp
index 7184c1cc8ce7d2ec8e109ef6686a643ccc26720b..8607d48533907c4d658bd9eafff4cdbe661f7542 100644
--- a/third_party/WebKit/Source/web/WebDocument.cpp
+++ b/third_party/WebKit/Source/web/WebDocument.cpp
@@ -137,6 +137,11 @@ bool WebDocument::isPluginDocument() const
     return constUnwrap<Document>()->isPluginDocument();
 }
 
+bool WebDocument::isPrefetchOnly() const
+{
+    return constUnwrap<Document>()->isPrefetchOnly();

[clamy, 2016/08/25 22:34:59]

How is isPrefetchOnly set on the document? Is this only true for no-state
prefetch?

[mattcary, 2016/08/26 08:17:51]

Yes, only true for no-state prefetch currently. It's set from the
PrerenderContents on the browser via the render frame, see here:

https://cs.chromium.org/chromium/src/chrome/browser/prerender/prerender_conte...

Currently prerender_contents is only set to be prefetch via a command-line flag.
There is discussion that as the nostate prefetch experiment evolves, we may set
it conditionally based on the prerender origin. Regardless, it's the prerender
manager/prerender contents that controls isPrefetchOnly.

+}
+
 WebURL WebDocument::baseURL() const
 {
     return constUnwrap<Document>()->baseURL();