PlzNavigate: add cancel navigation logic for uncommitted requests

content/browser/frame_host/navigation_request.cc

Index: content/browser/frame_host/navigation_request.cc
diff --git a/content/browser/frame_host/navigation_request.cc b/content/browser/frame_host/navigation_request.cc
index fb46ae59b3d9c10ad87d021dd60dd5010efb342f..1ce5ef238f2103f9bc5d13b641eb9339e1bc875c 100644
--- a/content/browser/frame_host/navigation_request.cc
+++ b/content/browser/frame_host/navigation_request.cc
@@ -13,25 +13,35 @@ namespace content {
 
 namespace {
 
+// The next available browser-global navigation request ID.
+static int64 next_navigation_request_id_ = 0;
+
 void OnBeginNavigation(const NavigationRequestInfo& info,
                        scoped_refptr<ResourceRequestBody> request_body,
+                       int64 navigation_request_id,
                        int64 frame_node_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  ResourceDispatcherHostImpl::Get()->NavigationRequest(
-      info, request_body, frame_node_id);
+  ResourceDispatcherHostImpl::Get()->StartNavigationRequest(
+      info, request_body, navigation_request_id, frame_node_id);
+}
+
+void CancelNavigationRequest(int64 navigation_request_id,
+                             int64 frame_node_id) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  ResourceDispatcherHostImpl::Get()->CancelNavigationRequest(
+      navigation_request_id, frame_node_id);
 }
 
 }  // namespace
 
 NavigationRequest::NavigationRequest(const NavigationRequestInfo& info,
                                      int64 frame_node_id)
-  : info_(info),
+  : navigation_request_id_(++next_navigation_request_id_),
+    info_(info),
     frame_node_id_(frame_node_id) {
 }
 
 NavigationRequest::~NavigationRequest() {
-  // TODO(clamy): Cancel the corresponding request in ResourceDispatcherHost if
-  // it has not commited yet.
 }
 
 void NavigationRequest::BeginNavigation(
@@ -40,7 +50,20 @@ void NavigationRequest::BeginNavigation(
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
-      base::Bind(&OnBeginNavigation, info_, request_body, frame_node_id_));
+      base::Bind(&OnBeginNavigation,
+                 info_,
+                 request_body,
+                 navigation_request_id_,
+                 frame_node_id_));
+}
+
+void NavigationRequest::CancelNavigation() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&CancelNavigationRequest,
+                 navigation_request_id_, frame_node_id_));
 }
 
 }  // namespace content