Adding WebContent-free Download

content/browser/download/download_request_core.cc

 // 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 "content/browser/download/download_resource_handler.h"
+#include "content/browser/download/download_request_core.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/thread_task_runner_handle.h"
 #include "content/browser/byte_stream.h"
 #include "content/browser/download/download_create_info.h"
 #include "content/browser/download/download_interrupt_reasons_impl.h"
 #include "content/browser/download/download_manager_impl.h"
-#include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/download_stats.h"
-#include "content/browser/loader/resource_dispatcher_host_impl.h"
-#include "content/browser/loader/resource_request_info_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_interrupt_reasons.h"
 #include "content/public/browser/download_item.h"
 #include "content/public/browser/download_manager_delegate.h"
 #include "content/public/browser/navigation_entry.h"
 #include "content/public/browser/power_save_blocker.h"
 #include "content/public/browser/web_contents.h"
-#include "content/public/common/resource_response.h"
 #include "net/base/io_buffer.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_status_code.h"
 #include "net/url_request/url_request_context.h"
 
 namespace content {
 
-struct DownloadResourceHandler::DownloadTabInfo {
-  GURL tab_url;
-  GURL tab_referrer_url;
-};
-
 namespace {
 
 void CallStartedCBOnUIThread(
     const DownloadUrlParameters::OnStartedCallback& started_cb,
     DownloadItem* item,
     DownloadInterruptReason interrupt_reason) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
   if (started_cb.is_null())
     return;
   started_cb.Run(item, interrupt_reason);
 }
 
 // Static function in order to prevent any accidental accesses to
-// DownloadResourceHandler members from the UI thread.
+// DownloadRequestCore members from the UI thread.
 static void StartOnUIThread(
     scoped_ptr<DownloadCreateInfo> info,
-    scoped_ptr<DownloadResourceHandler::DownloadTabInfo> tab_info,
     scoped_ptr<ByteStreamReader> stream,
+    base::WeakPtr<DownloadManager> download_manager,
     const DownloadUrlParameters::OnStartedCallback& started_cb) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
 
-  DownloadManager* download_manager = info->request_handle.GetDownloadManager();
   if (!download_manager) {
-    // NULL in unittests or if the page closed right after starting the
+    // nullptr in unittests or if the page closed right after starting the
     // download.
     if (!started_cb.is_null())
-      started_cb.Run(NULL, DOWNLOAD_INTERRUPT_REASON_USER_CANCELED);
+      started_cb.Run(nullptr, DOWNLOAD_INTERRUPT_REASON_USER_CANCELED);
 
     // |stream| gets deleted on non-FILE thread, but it's ok since
     // we're not using stream_writer_ yet.
 
     return;
   }
 
-  info->tab_url = tab_info->tab_url;
-  info->tab_referrer_url = tab_info->tab_referrer_url;
-
   download_manager->StartDownload(info.Pass(), stream.Pass(), started_cb);
 }
 
-void InitializeDownloadTabInfoOnUIThread(
-    const DownloadRequestHandle& request_handle,
-    DownloadResourceHandler::DownloadTabInfo* tab_info) {
-  DCHECK_CURRENTLY_ON(BrowserThread::UI);
-
-  WebContents* web_contents = request_handle.GetWebContents();
-  if (web_contents) {
-    NavigationEntry* entry = web_contents->GetController().GetVisibleEntry();
-    if (entry) {
-      tab_info->tab_url = entry->GetURL();
-      tab_info->tab_referrer_url = entry->GetReferrer().url;
-    }
-  }
-}
-
-void DeleteOnUIThread(
-    scoped_ptr<DownloadResourceHandler::DownloadTabInfo> tab_info) {}
-
 }  // namespace
 
-const int DownloadResourceHandler::kDownloadByteStreamSize = 100 * 1024;
+const int DownloadRequestCore::kDownloadByteStreamSize = 100 * 1024;
 
-DownloadResourceHandler::DownloadResourceHandler(
+DownloadRequestCore::DownloadRequestCore(
     uint32 id,
     net::URLRequest* request,
     const DownloadUrlParameters::OnStartedCallback& started_cb,
-    scoped_ptr<DownloadSaveInfo> save_info)
-    : ResourceHandler(request),
+    scoped_ptr<DownloadSaveInfo> save_info,
+    base::WeakPtr<DownloadManagerImpl> download_manager)
+    : request_(request),
       download_id_(id),
       started_cb_(started_cb),
       save_info_(save_info.Pass()),
-      tab_info_(new DownloadTabInfo()),
       last_buffer_size_(0),
       bytes_read_(0),
       pause_count_(0),
       was_deferred_(false),
-      on_response_started_called_(false) {
+      on_response_started_called_(false),
+      download_manager_(download_manager) {
   RecordDownloadCount(UNTHROTTLED_COUNT);
 
-  // Do UI thread initialization for tab_info_ asap after
-  // DownloadResourceHandler creation since the tab could be navigated
-  // before StartOnUIThread gets called.  This is safe because deletion
-  // will occur via PostTask() as well, which will serialized behind this
-  // PostTask()
-  const ResourceRequestInfoImpl* request_info = GetRequestInfo();
-  BrowserThread::PostTask(
-      BrowserThread::UI, FROM_HERE,
-      base::Bind(&InitializeDownloadTabInfoOnUIThread,
-                 DownloadRequestHandle(AsWeakPtr(), request_info->GetChildID(),
-                                       request_info->GetRouteID(),
-                                       request_info->GetRequestID(),
-                                       request_info->frame_tree_node_id()),
-                 tab_info_.get()));
   power_save_blocker_ = PowerSaveBlocker::Create(
       PowerSaveBlocker::kPowerSaveBlockPreventAppSuspension,
       PowerSaveBlocker::kReasonOther, "Download in progress");
 }
 
-bool DownloadResourceHandler::OnRequestRedirected(
-    const net::RedirectInfo& redirect_info,
-    ResourceResponse* response,
-    bool* defer) {
-  return true;
+DownloadRequestCore::~DownloadRequestCore() {
+  DCHECK_CURRENTLY_ON(BrowserThread::IO);
+
+  // This won't do anything if the callback was called before.
+  // If it goes through, it will likely be because OnWillStart() returned
+  // false somewhere in the chain of resource handlers.
+  CallStartedCB(nullptr, DOWNLOAD_INTERRUPT_REASON_NETWORK_FAILED);
+
+  // Remove output stream callback if a stream exists.
+  if (stream_writer_)
+    stream_writer_->RegisterCallback(base::Closure());
+
+  UMA_HISTOGRAM_TIMES("SB2.DownloadDuration",
+                      base::TimeTicks::Now() - download_start_time_);
 }
 
 // Send the download creation information to the download thread.
-bool DownloadResourceHandler::OnResponseStarted(
-    ResourceResponse* response,
-    bool* defer) {
+bool DownloadRequestCore::OnResponseStarted() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   // There can be only one (call)
   DCHECK(!on_response_started_called_);
   on_response_started_called_ = true;
 
   DVLOG(20) << __FUNCTION__ << "()" << DebugString();
   download_start_time_ = base::TimeTicks::Now();
 
   // If it's a download, we don't want to poison the cache with it.
   request()->StopCaching();
 
   // Lower priority as well, so downloads don't contend for resources
   // with main frames.
   request()->SetPriority(net::IDLE);
 
   // If the content-length header is not present (or contains something other
   // than numbers), the incoming content_length is -1 (unknown size).
   // Set the content length to 0 to indicate unknown size to DownloadManager.
-  int64 content_length =
-      response->head.content_length > 0 ? response->head.content_length : 0;
-
-  const ResourceRequestInfoImpl* request_info = GetRequestInfo();
+  int64 content_length = request()->GetExpectedContentSize() > 0
+                             ? request()->GetExpectedContentSize()
+                             : 0;
 
   // Deleted in DownloadManager.
-  scoped_ptr<DownloadCreateInfo> info(
-      new DownloadCreateInfo(base::Time::Now(),
-                             content_length,
-                             request()->net_log(),
-                             request_info->HasUserGesture(),
-                             request_info->GetPageTransition(),
-                             save_info_.Pass()));
+  scoped_ptr<DownloadCreateInfo> info(new DownloadCreateInfo(
+      base::Time::Now(), content_length, request()->net_log(), false,
+      ui::PAGE_TRANSITION_LINK, save_info_.Pass()));
 
   // Create the ByteStream for sending data to the download sink.
   scoped_ptr<ByteStreamReader> stream_reader;
   CreateByteStream(
       base::ThreadTaskRunnerHandle::Get(),
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE),
       kDownloadByteStreamSize, &stream_writer_, &stream_reader);
   stream_writer_->RegisterCallback(
-      base::Bind(&DownloadResourceHandler::ResumeRequest, AsWeakPtr()));
+      base::Bind(&DownloadRequestCore::ResumeRequest, AsWeakPtr()));
 
   info->download_id = download_id_;
   info->url_chain = request()->url_chain();
   info->referrer_url = GURL(request()->referrer());
-  info->mime_type = response->head.mime_type;
+  string mime_type;
+  request()->GetMimeType(&mime_type);
+  info->mime_type = mime_type;
   info->remote_address = request()->GetSocketAddress().host();
   if (request()->response_headers()) {
     // Grab the first content-disposition header.  There may be more than one,
     // though as of this writing, the network stack ensures if there are, they
     // are all duplicates.
     request()->response_headers()->EnumerateHeader(
         nullptr, "content-disposition", &info->content_disposition);
   }
   RecordDownloadMimeType(info->mime_type);
   RecordDownloadContentDisposition(info->content_disposition);
 
-  info->request_handle = DownloadRequestHandle(
-      AsWeakPtr(), request_info->GetChildID(), request_info->GetRouteID(),
-      request_info->GetRequestID(), request_info->frame_tree_node_id());
-
   // Get the last modified time and etag.
   const net::HttpResponseHeaders* headers = request()->response_headers();
   if (headers) {
     if (headers->HasStrongValidators()) {
       // If we don't have strong validators as per RFC 2616 section 13.3.3, then
       // we neither store nor use them for range requests.
-      if (!headers->EnumerateHeader(NULL, "Last-Modified",
+      if (!headers->EnumerateHeader(nullptr, "Last-Modified",
                                     &info->last_modified))
         info->last_modified.clear();
-      if (!headers->EnumerateHeader(NULL, "ETag", &info->etag))
+      if (!headers->EnumerateHeader(nullptr, "ETag", &info->etag))
         info->etag.clear();
     }
 
     int status = headers->response_code();
-    if (2 == status / 100  && status != net::HTTP_PARTIAL_CONTENT) {
+    if (2 == status / 100 && status != net::HTTP_PARTIAL_CONTENT) {
       // Success & not range response; if we asked for a range, we didn't
       // get it--reset the file pointers to reflect that.
       info->save_info->offset = 0;
       info->save_info->hash_state = "";
     }
 
     if (!headers->GetMimeType(&info->original_mime_type))
       info->original_mime_type.clear();
   }
 
   // Blink verifies that the requester of this download is allowed to set a
   // suggested name for the security origin of the downlaod URL. However, this
   // assumption doesn't hold if there were cross origin redirects. Therefore,
   // clear the suggested_name for such requests.
   if (info->url_chain.size() > 1 &&
       info->url_chain.front().GetOrigin() != info->url_chain.back().GetOrigin())
     info->save_info->suggested_name.clear();
 
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
-      base::Bind(&StartOnUIThread,
-                 base::Passed(&info),
-                 base::Passed(&tab_info_),
-                 base::Passed(&stream_reader),
+      base::Bind(&StartOnUIThread, base::Passed(&info),
+                 base::Passed(&stream_reader), download_manager_,
                  // Pass to StartOnUIThread so that variable
                  // access is always on IO thread but function
                  // is called on UI thread.
                  started_cb_));
   // Guaranteed to be called in StartOnUIThread
   started_cb_.Reset();
 
   return true;
 }
 
-void DownloadResourceHandler::CallStartedCB(
+void DownloadRequestCore::CallStartedCB(
     DownloadItem* item,
     DownloadInterruptReason interrupt_reason) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   if (started_cb_.is_null())
     return;
-  BrowserThread::PostTask(
-      BrowserThread::UI,
-      FROM_HERE,
-      base::Bind(
-          &CallStartedCBOnUIThread, started_cb_, item, interrupt_reason));
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          base::Bind(&CallStartedCBOnUIThread, started_cb_,
+                                     item, interrupt_reason));
   started_cb_.Reset();
 }
 
-bool DownloadResourceHandler::OnWillStart(const GURL& url, bool* defer) {
-  return true;
-}
-
-bool DownloadResourceHandler::OnBeforeNetworkStart(const GURL& url,
-                                                   bool* defer) {
-  return true;
-}
-
 // Create a new buffer, which will be handed to the download thread for file
 // writing and deletion.
-bool DownloadResourceHandler::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
-                                         int* buf_size,
-                                         int min_size) {
+bool DownloadRequestCore::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
+                                     int* buf_size,
+                                     int min_size) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(buf && buf_size);
   DCHECK(!read_buffer_.get());
 
   *buf_size = min_size < 0 ? kReadBufSize : min_size;
   last_buffer_size_ = *buf_size;
   read_buffer_ = new net::IOBuffer(*buf_size);
   *buf = read_buffer_.get();
   return true;
 }
 
 // Pass the buffer to the download file writer.
-bool DownloadResourceHandler::OnReadCompleted(int bytes_read, bool* defer) {
+bool DownloadRequestCore::OnReadCompleted(int bytes_read, bool* defer) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(read_buffer_.get());
 
   base::TimeTicks now(base::TimeTicks::Now());
   if (!last_read_time_.is_null()) {
     double seconds_since_last_read = (now - last_read_time_).InSecondsF();
     if (now == last_read_time_)
       // Use 1/10 ms as a "very small number" so that we avoid
       // divide-by-zero error and still record a very high potential bandwidth.
       seconds_since_last_read = 0.00001;
 
-    double actual_bandwidth = (bytes_read)/seconds_since_last_read;
-    double potential_bandwidth = last_buffer_size_/seconds_since_last_read;
+    double actual_bandwidth = (bytes_read) / seconds_since_last_read;
+    double potential_bandwidth = last_buffer_size_ / seconds_since_last_read;
     RecordBandwidth(actual_bandwidth, potential_bandwidth);
   }
   last_read_time_ = now;
 
   if (!bytes_read)
     return true;
   bytes_read_ += bytes_read;
   DCHECK(read_buffer_.get());
 
   // Take the data ship it down the stream.  If the stream is full, pause the
   // request; the stream callback will resume it.
   if (!stream_writer_->Write(read_buffer_, bytes_read)) {
     PauseRequest();
     *defer = was_deferred_ = true;
     last_stream_pause_time_ = now;
   }
 
   read_buffer_ = NULL;  // Drop our reference.
 
   if (pause_count_ > 0)
     *defer = was_deferred_ = true;
 
   return true;
 }
 
-void DownloadResourceHandler::OnResponseCompleted(
-    const net::URLRequestStatus& status,
-    const std::string& security_info,
-    bool* defer) {
+void DownloadRequestCore::OnResponseCompleted(
+    const net::URLRequestStatus& status) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   int response_code = status.is_success() ? request()->GetResponseCode() : 0;
   DVLOG(20) << __FUNCTION__ << "()" << DebugString()
             << " status.status() = " << status.status()
             << " status.error() = " << status.error()
             << " response_code = " << response_code;
 
   net::Error error_code = net::OK;
   if (status.status() == net::URLRequestStatus::FAILED ||
       // Note cancels as failures too.
       status.status() == net::URLRequestStatus::CANCELED) {
     error_code = static_cast<net::Error>(status.error());  // Normal case.
     // Make sure that at least the fact of failure comes through.
     if (error_code == net::OK)
       error_code = net::ERR_FAILED;
   }
 
   // ERR_CONTENT_LENGTH_MISMATCH and ERR_INCOMPLETE_CHUNKED_ENCODING are
   // allowed since a number of servers in the wild close the connection too
   // early by mistake. Other browsers - IE9, Firefox 11.0, and Safari 5.1.4 -
   // treat downloads as complete in both cases, so we follow their lead.
   if (error_code == net::ERR_CONTENT_LENGTH_MISMATCH ||
       error_code == net::ERR_INCOMPLETE_CHUNKED_ENCODING) {
     error_code = net::OK;
   }
-  DownloadInterruptReason reason =
-      ConvertNetErrorToInterruptReason(
-        error_code, DOWNLOAD_INTERRUPT_FROM_NETWORK);
+  DownloadInterruptReason reason = ConvertNetErrorToInterruptReason(
+      error_code, DOWNLOAD_INTERRUPT_FROM_NETWORK);
 
   if (status.status() == net::URLRequestStatus::CANCELED &&
       status.error() == net::ERR_ABORTED) {
     // CANCELED + ERR_ABORTED == something outside of the network
     // stack cancelled the request.  There aren't that many things that
     // could do this to a download request (whose lifetime is separated from
     // the tab from which it came).  We map this to USER_CANCELLED as the
     // case we know about (system suspend because of laptop close) corresponds
     // to a user action.
     // TODO(ahendrickson) -- Find a better set of codes to use here, as
     // CANCELED/ERR_ABORTED can occur for reasons other than user cancel.
     if (net::IsCertStatusError(request()->ssl_info().cert_status))
       reason = DOWNLOAD_INTERRUPT_REASON_SERVER_CERT_PROBLEM;
     else
       reason = DOWNLOAD_INTERRUPT_REASON_USER_CANCELED;
   }
 
-  if (status.is_success() &&
-      reason == DOWNLOAD_INTERRUPT_REASON_NONE &&
+  if (status.is_success() && reason == DOWNLOAD_INTERRUPT_REASON_NONE &&
       request()->response_headers()) {
     // Handle server's response codes.
-    switch(response_code) {
-      case -1:                          // Non-HTTP request.
+    switch (response_code) {
+      case -1:  // Non-HTTP request.
       case net::HTTP_OK:
       case net::HTTP_CREATED:
       case net::HTTP_ACCEPTED:
       case net::HTTP_NON_AUTHORITATIVE_INFORMATION:
       case net::HTTP_RESET_CONTENT:
       case net::HTTP_PARTIAL_CONTENT:
         // Expected successful codes.
         break;
       case net::HTTP_NO_CONTENT:
       case net::HTTP_NOT_FOUND:
@@ skipping 10 matching lines @@
         reason = DOWNLOAD_INTERRUPT_REASON_SERVER_NO_RANGE;
         break;
       case net::HTTP_UNAUTHORIZED:
         // Server didn't authorize this request.
         reason = DOWNLOAD_INTERRUPT_REASON_SERVER_UNAUTHORIZED;
         break;
       case net::HTTP_FORBIDDEN:
         // Server forbids access to this resource.
         reason = DOWNLOAD_INTERRUPT_REASON_SERVER_FORBIDDEN;
         break;
-      default:    // All other errors.
+      default:  // All other errors.
         // Redirection and informational codes should have been handled earlier
         // in the stack.
         DCHECK_NE(3, response_code / 100);
         DCHECK_NE(1, response_code / 100);
         reason = DOWNLOAD_INTERRUPT_REASON_SERVER_FAILED;
         break;
     }
   }
 
   std::string accept_ranges;
   bool has_strong_validators = false;
   if (request()->response_headers()) {
-    request()->response_headers()->EnumerateHeader(
-        NULL, "Accept-Ranges", &accept_ranges);
+    request()->response_headers()->EnumerateHeader(nullptr, "Accept-Ranges",
+                                                   &accept_ranges);
     has_strong_validators =
         request()->response_headers()->HasStrongValidators();
   }
   RecordAcceptsRanges(accept_ranges, bytes_read_, has_strong_validators);
   RecordNetworkBlockage(base::TimeTicks::Now() - download_start_time_,
                         total_pause_time_);
 
-  CallStartedCB(NULL, reason);
+  CallStartedCB(nullptr, reason);
 
   // Send the info down the stream.  Conditional is in case we get
   // OnResponseCompleted without OnResponseStarted.
   if (stream_writer_)
     stream_writer_->Close(reason);
 
   // If the error mapped to something unknown, record it so that
   // we can drill down.
   if (reason == DOWNLOAD_INTERRUPT_REASON_NETWORK_FAILED) {
     UMA_HISTOGRAM_SPARSE_SLOWLY("Download.MapErrorNetworkFailed",
                                 std::abs(status.error()));
   }
 
   stream_writer_.reset();  // We no longer need the stream.
-  read_buffer_ = NULL;
+  read_buffer_ = nullptr;
 }
 
-void DownloadResourceHandler::OnDataDownloaded(int bytes_downloaded) {
-  NOTREACHED();
-}
-
-void DownloadResourceHandler::PauseRequest() {
+void DownloadRequestCore::PauseRequest() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
 
   ++pause_count_;
 }
 
-void DownloadResourceHandler::ResumeRequest() {
+void DownloadRequestCore::ResumeRequest() {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK_LT(0, pause_count_);
 
   --pause_count_;
 
   if (!was_deferred_)
     return;
   if (pause_count_ > 0)
     return;
 
   was_deferred_ = false;
   if (!last_stream_pause_time_.is_null()) {
     total_pause_time_ += (base::TimeTicks::Now() - last_stream_pause_time_);
     last_stream_pause_time_ = base::TimeTicks();
   }
 
-  controller()->Resume();
+  downloader_->ResumeReading();
 }
 
-void DownloadResourceHandler::CancelRequest() {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  const ResourceRequestInfoImpl* info = GetRequestInfo();
-  ResourceDispatcherHostImpl::Get()->CancelRequest(
-      info->GetChildID(),
-      info->GetRequestID());
-  // This object has been deleted.
-}
-
-std::string DownloadResourceHandler::DebugString() const {
-  const ResourceRequestInfoImpl* info = GetRequestInfo();
-  return base::StringPrintf("{"
-                            " url_ = " "\"%s\""
-                            " info = {"
-                            " child_id = " "%d"
-                            " request_id = " "%d"
-                            " route_id = " "%d"
-                            " }"
-                            " }",
-                            request() ?
-                                request()->url().spec().c_str() :
-                                "<NULL request>",
-                            info->GetChildID(),
-                            info->GetRequestID(),
-                            info->GetRouteID());
-}
-
-DownloadResourceHandler::~DownloadResourceHandler() {
-  DCHECK_CURRENTLY_ON(BrowserThread::IO);
-
-  // This won't do anything if the callback was called before.
-  // If it goes through, it will likely be because OnWillStart() returned
-  // false somewhere in the chain of resource handlers.
-  CallStartedCB(NULL, DOWNLOAD_INTERRUPT_REASON_NETWORK_FAILED);
-
-  // Remove output stream callback if a stream exists.
-  if (stream_writer_)
-    stream_writer_->RegisterCallback(base::Closure());
-
-  // tab_info_ must be destroyed on UI thread, since
-  // InitializeDownloadTabInfoOnUIThread might still be using it.
-  if (tab_info_.get()) {
-    BrowserThread::PostTask(
-        BrowserThread::UI, FROM_HERE,
-        base::Bind(&DeleteOnUIThread, base::Passed(&tab_info_)));
-  }
-
-  UMA_HISTOGRAM_TIMES("SB2.DownloadDuration",
-                      base::TimeTicks::Now() - download_start_time_);
+std::string DownloadRequestCore::DebugString() const {
+  return base::StringPrintf(
+      "{"
+      " url_ = "
+      "\"%s\""
+      " }",
+      request() ? request()->url().spec().c_str() : "<NULL request>");
 }
 
 }  // namespace content