Make PrerenderHandle an observer of PrerenderContents.

chrome/renderer/prerender/prerender_dispatcher.cc

Index: chrome/renderer/prerender/prerender_dispatcher.cc
diff --git a/chrome/renderer/prerender/prerender_dispatcher.cc b/chrome/renderer/prerender/prerender_dispatcher.cc
index a3f72ec5798c2a26acdfbeb7a92d96bb2664a472..013ca9ab5c408e887e5c384c869a2b96db1338d6 100644
--- a/chrome/renderer/prerender/prerender_dispatcher.cc
+++ b/chrome/renderer/prerender/prerender_dispatcher.cc
@@ -7,55 +7,74 @@
 #include "base/logging.h"
 #include "chrome/common/prerender_messages.h"
 #include "chrome/renderer/prerender/prerender_extra_data.h"
+#include "content/public/common/referrer.h"
 #include "content/public/renderer/render_thread.h"
+#include "content/public/renderer/render_view.h"
 #include "googleurl/src/gurl.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebPrerenderingSupport.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebString.h"
+#include "third_party/WebKit/Source/Platform/chromium/public/WebURL.h"
 
 namespace prerender {
 
+using WebKit::WebPrerender;
+using WebKit::WebPrerenderingSupport;
+
 PrerenderDispatcher::PrerenderDispatcher() {
-  WebKit::WebPrerenderingSupport::initialize(this);
+  WebPrerenderingSupport::initialize(this);
 }
 
 PrerenderDispatcher::~PrerenderDispatcher() {
-  WebKit::WebPrerenderingSupport::shutdown();
+  WebPrerenderingSupport::shutdown();
 }
 
 bool PrerenderDispatcher::IsPrerenderURL(const GURL& url) const {
-  return prerender_urls_.find(url) != prerender_urls_.end();
+  return running_prerender_urls_.count(url) >= 1;
 }
 
-void PrerenderDispatcher::OnAddPrerenderURL(const GURL& url) {
-  PrerenderMap::iterator it = prerender_urls_.find(url);
-  if (it != prerender_urls_.end()) {
-    DCHECK_LT(0, it->second);
-    it->second += 1;
-  } else {
-    prerender_urls_[url] = 1;
-  }
+void PrerenderDispatcher::OnPrerenderStart(int prerender_id) {
+  DCHECK_NE(0u, prerenders_.count(prerender_id));
+  std::map<int, GURL>::iterator it = prerenders_.find(prerender_id);
+  const GURL& url = it->second;
+  running_prerender_urls_.insert(
+      std::multimap<GURL, int>::value_type(url, prerender_id));
 }
 
-void PrerenderDispatcher::OnRemovePrerenderURL(const GURL& url) {
-  PrerenderMap::iterator it = prerender_urls_.find(url);
-  // This is possible with a spurious remove.
+void PrerenderDispatcher::OnPrerenderAddAlias(int prerender_id,
+                                              const GURL& url) {
+  DCHECK_NE(0u, prerenders_.count(prerender_id));
+  running_prerender_urls_.insert(
+      std::multimap<GURL, int>::value_type(url, prerender_id));
+}
+
+void PrerenderDispatcher::OnPrerenderStop(int prerender_id) {
+  DCHECK_NE(0u, prerenders_.count(prerender_id));
+
   // TODO(cbentzel): We'd also want to send the map of active prerenders when
   // creating a new render process, so the Add/Remove go relative to that.
   // This may not be that big of a deal in practice, since the newly created tab
   // is unlikely to go to the prerendered page.
-  if (it == prerender_urls_.end())
-    return;
-  DCHECK_LT(0, it->second);
-  it->second -= 1;
-  if (it->second == 0)
-    prerender_urls_.erase(it);
+  prerenders_.erase(prerender_id);
+
+  std::multimap<GURL, int>::iterator it = running_prerender_urls_.begin();
+  while (it != running_prerender_urls_.end()) {
+    std::multimap<GURL, int>::iterator next = it;
+    ++next;
+
+    if (it->second == prerender_id)
+      running_prerender_urls_.erase(it);
+
+    it = next;
+  }
 }
 
 bool PrerenderDispatcher::OnControlMessageReceived(
     const IPC::Message& message) {
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PrerenderDispatcher, message)
-    IPC_MESSAGE_HANDLER(PrerenderMsg_AddPrerenderURL, OnAddPrerenderURL)
-    IPC_MESSAGE_HANDLER(PrerenderMsg_RemovePrerenderURL, OnRemovePrerenderURL)
+    IPC_MESSAGE_HANDLER(PrerenderMsg_OnPrerenderStart, OnPrerenderStart)
+    IPC_MESSAGE_HANDLER(PrerenderMsg_OnPrerenderAddAlias, OnPrerenderAddAlias)
+    IPC_MESSAGE_HANDLER(PrerenderMsg_OnPrerenderStop, OnPrerenderStop)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -65,6 +84,8 @@ bool PrerenderDispatcher::OnControlMessageReceived(
 void PrerenderDispatcher::add(const WebKit::WebPrerender& prerender) {
   const PrerenderExtraData& extra_data =
       PrerenderExtraData::FromPrerender(prerender);
+  prerenders_[extra_data.prerender_id()] = prerender.url();
+
   content::RenderThread::Get()->Send(new PrerenderHostMsg_AddLinkRelPrerender(
       extra_data.prerender_id(), GURL(prerender.url()),
       content::Referrer(GURL(prerender.referrer()), prerender.referrerPolicy()),