Eliminate ResourceDispatcherHostDelegate::ShouldDeferStart in favor of ResourceThrottle.

Also, eliminates direct use of ResourceDispatcherHost::{CancelPendingRequest,StartDeferredRequest} in prerender_tracker.cc.

Review URL: http://codereview.chromium.org/9384028

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@122560 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 104 insertions, 26 deletions

diff --git a/chrome/browser/prerender/prerender_resource_throttle.cc b/chrome/browser/prerender/prerender_resource_throttle.cc
new file mode 100644
index 0000000..df4be12
--- /dev/null
+++ b/chrome/browser/prerender/prerender_resource_throttle.cc
@@ -0,0 +1,42 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/prerender/prerender_resource_throttle.h"
+
+#include "base/bind.h"
+#include "chrome/browser/prerender/prerender_tracker.h"
+#include "content/public/browser/resource_throttle_controller.h"
+#include "net/url_request/url_request.h"
+
+namespace prerender {
+
+PrerenderResourceThrottle::PrerenderResourceThrottle(
+    PrerenderTracker* prerender_tracker,
+    const net::URLRequest* request,
+    int child_id,
+    int route_id)
+    : prerender_tracker_(prerender_tracker),
+      request_(request),
+      child_id_(child_id),
+      route_id_(route_id) {
+}
+
+PrerenderResourceThrottle::~PrerenderResourceThrottle() {
+}
+
+void PrerenderResourceThrottle::WillStartRequest(bool* defer) {
+  *defer = prerender_tracker_->PotentiallyDelayRequestOnIOThread(
+      request_->url(), child_id_, route_id_,
+      base::Bind(&PrerenderResourceThrottle::ContinueRequest, AsWeakPtr()));
+}
+
+void PrerenderResourceThrottle::ContinueRequest(bool proceed) {
+  if (proceed) {
+    controller()->Resume();
+  } else {
+    controller()->Cancel();
+  }
+}
+
+}  // namespace prerender
diff --git a/chrome/browser/prerender/prerender_resource_throttle.h b/chrome/browser/prerender/prerender_resource_throttle.h
new file mode 100644
index 0000000..e6fc3ae
--- /dev/null
+++ b/chrome/browser/prerender/prerender_resource_throttle.h
@@ -0,0 +1,49 @@
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_
+#define CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_
+#pragma once
+
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/resource_throttle.h"
+
+namespace net {
+class URLRequest;
+}
+
+namespace prerender {
+class PrerenderTracker;
+
+class PrerenderResourceThrottle
+    : public content::ResourceThrottle,
+      public base::SupportsWeakPtr<PrerenderResourceThrottle> {
+ public:
+  PrerenderResourceThrottle(PrerenderTracker* prerender_tracker,
+                            const net::URLRequest* request,
+                            int child_id,
+                            int route_id);
+
+  // content::ResourceThrottle implementation:
+  virtual void WillStartRequest(bool* defer) OVERRIDE;
+
+ private:
+  virtual ~PrerenderResourceThrottle();
+
+  void ContinueRequest(bool proceed);
+
+  PrerenderTracker* prerender_tracker_;
+  const net::URLRequest* request_;
+  int child_id_;
+  int route_id_;
+  int request_id_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrerenderResourceThrottle);
+};
+
+}  // namespace prerender
+
+#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_RESOURCE_THROTTLE_H_
diff --git a/chrome/browser/prerender/prerender_tracker.cc b/chrome/browser/prerender/prerender_tracker.cc
index b82be79..8672762 100644
--- a/chrome/browser/prerender/prerender_tracker.cc
+++ b/chrome/browser/prerender/prerender_tracker.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -20,16 +20,6 @@ namespace prerender {
 
 namespace {
 
-void CancelDeferredRequestOnIOThread(int child_id, int request_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  ResourceDispatcherHost::Get()->CancelRequest(child_id, request_id, false);
-}
-
-void StartDeferredRequestOnIOThread(int child_id, int request_id) {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  ResourceDispatcherHost::Get()->StartDeferredRequest(child_id, request_id);
-}
-
 bool ShouldCancelRequest(
     int child_id,
     int route_id) {
@@ -53,17 +43,11 @@ bool ShouldCancelRequest(
 void HandleDelayedRequestOnUIThread(
     int child_id,
     int route_id,
-    int request_id) {
+    const PrerenderTracker::CheckURLCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  if (ShouldCancelRequest(child_id, route_id)) {
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&CancelDeferredRequestOnIOThread, child_id, request_id));
-  } else {
-    BrowserThread::PostTask(
-        BrowserThread::IO, FROM_HERE,
-        base::Bind(&StartDeferredRequestOnIOThread, child_id, request_id));
-  }
+  bool should_cancel = ShouldCancelRequest(child_id, route_id);
+  BrowserThread::PostTask(
+      BrowserThread::IO, FROM_HERE, base::Bind(callback, !should_cancel));
 }
 
 void DestroyPrerenderForRenderViewOnUI(
@@ -189,7 +173,7 @@ bool PrerenderTracker::PotentiallyDelayRequestOnIOThread(
     const GURL& gurl,
     int process_id,
     int route_id,
-    int request_id) {
+    const CheckURLCallback& callback) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   if (!url_counter_.MatchesURL(gurl))
     return false;
@@ -197,7 +181,7 @@ bool PrerenderTracker::PotentiallyDelayRequestOnIOThread(
       BrowserThread::UI,
       FROM_HERE,
       base::Bind(&HandleDelayedRequestOnUIThread, process_id, route_id,
-                 request_id));
+                 callback));
   return true;
 }
 
diff --git a/chrome/browser/prerender/prerender_tracker.h b/chrome/browser/prerender/prerender_tracker.h
index 5a3e138..56d5dff 100644
--- a/chrome/browser/prerender/prerender_tracker.h
+++ b/chrome/browser/prerender/prerender_tracker.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
@@ -47,6 +47,8 @@ class URLCounter : public base::NonThreadSafe {
 // and can be modified on any thread.
 class PrerenderTracker {
  public:
+  typedef base::Callback<void(bool /* proceed */)> CheckURLCallback;
+
   PrerenderTracker();
   ~PrerenderTracker();
 
@@ -78,12 +80,13 @@ class PrerenderTracker {
                            FinalStatus final_status);
 
   // Potentially delay a resource request on the IO thread to prevent a double
-  // get.
+  // get.  When this method returns true, the callback will be run later to
+  // indicate if the request should be allowed or canceled.
   bool PotentiallyDelayRequestOnIOThread(
       const GURL& gurl,
       int child_id,
       int route_id,
-      int request_id);
+      const CheckURLCallback& callback);
 
   void AddPrerenderURLOnUIThread(const GURL& url);
   void RemovePrerenderURLsOnUIThread(const std::vector<GURL>& urls);