base::Bind: Convert printing_message_filter.cc.

This file superfluously used CancelableTask. I cleaned up around the areas I
touched.

BUG=none
TEST=none

R=csilv@chromium.org

Review URL: http://codereview.chromium.org/8718001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@111810 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 43 insertions, 74 deletions

diff --git a/chrome/browser/printing/printer_query.cc b/chrome/browser/printing/printer_query.cc
index b70228a..0536b24 100644
--- a/chrome/browser/printing/printer_query.cc
+++ b/chrome/browser/printing/printer_query.cc
@@ -27,11 +27,6 @@ PrinterQuery::~PrinterQuery() {
   DCHECK(!is_print_dialog_box_shown_);
   // If this fires, it is that this pending printer context has leaked.
   DCHECK(!worker_.get());
-  if (callback_.get()) {
-    // Be sure to cancel it.
-    callback_->Cancel();
-  }
-  // It may get deleted in a different thread that the one that created it.
 }
 
 void PrinterQuery::GetSettingsDone(const PrintSettings& new_settings,
@@ -45,18 +40,18 @@ void PrinterQuery::GetSettingsDone(const PrintSettings& new_settings,
     // Failure.
     cookie_ = 0;
   }
-  if (callback_.get()) {
+
+  if (!callback_.is_null()) {
     // This may cause reentrancy like to call StopWorker().
-    callback_->Run();
-    callback_.reset(NULL);
+    callback_.Run();
+    callback_.Reset();
   }
 }
 
 PrintJobWorker* PrinterQuery::DetachWorker(PrintJobWorkerOwner* new_owner) {
-  DCHECK(!callback_.get());
+  DCHECK(callback_.is_null());
   DCHECK(worker_.get());
-  if (!worker_.get())
-    return NULL;
+
   worker_->SetNewOwner(new_owner);
   return worker_.release();
 }
@@ -78,11 +73,11 @@ void PrinterQuery::GetSettings(GetSettingsAskParam ask_user_for_settings,
                                int expected_page_count,
                                bool has_selection,
                                MarginType margin_type,
-                               CancelableTask* callback) {
+                               const base::Closure& callback) {
   DCHECK_EQ(io_message_loop_, MessageLoop::current());
   DCHECK(!is_print_dialog_box_shown_);
-  if (!StartWorker(callback))
-    return;
+
+  StartWorker(callback);
 
   // Real work is done in PrintJobWorker::Init().
   is_print_dialog_box_shown_ = ask_user_for_settings == ASK_USER;
@@ -95,9 +90,8 @@ void PrinterQuery::GetSettings(GetSettingsAskParam ask_user_for_settings,
 }
 
 void PrinterQuery::SetSettings(const DictionaryValue& new_settings,
-                               CancelableTask* callback) {
-  if (!StartWorker(callback))
-    return;
+                               const base::Closure& callback) {
+  StartWorker(callback);
 
   worker_->message_loop()->PostTask(
       FROM_HERE,
@@ -106,25 +100,15 @@ void PrinterQuery::SetSettings(const DictionaryValue& new_settings,
                  new_settings.DeepCopy()));
 }
 
-bool PrinterQuery::StartWorker(CancelableTask* callback) {
-  DCHECK(!callback_.get());
+void PrinterQuery::StartWorker(const base::Closure& callback) {
+  DCHECK(callback_.is_null());
   DCHECK(worker_.get());
-  if (!worker_.get())
-    return false;
-
-  // Lazy create the worker thread. There is one worker thread per print job.
-  if (!worker_->message_loop()) {
-    if (!worker_->Start()) {
-      if (callback) {
-        callback->Cancel();
-        delete callback;
-      }
-      NOTREACHED();
-      return false;
-    }
-  }
-  callback_.reset(callback);
-  return true;
+
+  // Lazily create the worker thread. There is one worker thread per print job.
+  if (!worker_->message_loop())
+    worker_->Start();
+
+  callback_ = callback;
 }
 
 void PrinterQuery::StopWorker() {
@@ -139,7 +123,7 @@ void PrinterQuery::StopWorker() {
 }
 
 bool PrinterQuery::is_callback_pending() const {
-  return callback_.get() != NULL;
+  return !callback_.is_null();
 }
 
 bool PrinterQuery::is_valid() const {
diff --git a/chrome/browser/printing/printer_query.h b/chrome/browser/printing/printer_query.h
index 3add3e4..dcb2f6a 100644
--- a/chrome/browser/printing/printer_query.h
+++ b/chrome/browser/printing/printer_query.h
@@ -6,13 +6,13 @@
 #define CHROME_BROWSER_PRINTING_PRINTER_QUERY_H_
 #pragma once
 
+#include "base/callback.h"
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "chrome/browser/printing/print_job_worker_owner.h"
 #include "printing/print_job_constants.h"
 #include "ui/gfx/native_widget_types.h"
 
-class CancelableTask;
 class MessageLoop;
 
 namespace base {
@@ -51,11 +51,11 @@ class PrinterQuery : public PrintJobWorkerOwner {
                    int expected_page_count,
                    bool has_selection,
                    MarginType margin_type,
-                   CancelableTask* callback);
+                   const base::Closure& callback);
 
   // Updates the current settings with |new_settings| dictionary values.
   void SetSettings(const base::DictionaryValue& new_settings,
-                   CancelableTask* callback);
+                   const base::Closure& callback);
 
   // Stops the worker thread since the client is done with this object.
   void StopWorker();
@@ -72,8 +72,7 @@ class PrinterQuery : public PrintJobWorkerOwner {
   virtual ~PrinterQuery();
 
   // Lazy create the worker thread. There is one worker thread per print job.
-  // Returns true, if worker thread exists or has been created.
-  bool StartWorker(CancelableTask* callback);
+  void StartWorker(const base::Closure& callback);
 
   // Main message loop reference. Used to send notifications in the right
   // thread.
@@ -96,8 +95,8 @@ class PrinterQuery : public PrintJobWorkerOwner {
   // Results from the last GetSettingsDone() callback.
   PrintingContext::Result last_status_;
 
-  // Task waiting to be executed.
-  scoped_ptr<CancelableTask> callback_;
+  // Callback waiting to be run.
+  base::Closure callback_;
 
   DISALLOW_COPY_AND_ASSIGN(PrinterQuery);
 };
diff --git a/chrome/browser/printing/printing_message_filter.cc b/chrome/browser/printing/printing_message_filter.cc
index a497bba..fc5723e 100644
--- a/chrome/browser/printing/printing_message_filter.cc
+++ b/chrome/browser/printing/printing_message_filter.cc
@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "base/bind.h"
 #include "base/process_util.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/printing/printer_query.h"
@@ -181,23 +182,16 @@ void PrintingMessageFilter::OnGetDefaultPrintSettings(IPC::Message* reply_msg) {
   }
 
   print_job_manager_->PopPrinterQuery(0, &printer_query);
-  if (!printer_query.get()) {
+  if (!printer_query.get())
     printer_query = new printing::PrinterQuery;
-  }
 
-  CancelableTask* task = NewRunnableMethod(
-      this,
-      &PrintingMessageFilter::OnGetDefaultPrintSettingsReply,
-      printer_query,
-      reply_msg);
   // Loads default settings. This is asynchronous, only the IPC message sender
   // will hang until the settings are retrieved.
-  printer_query->GetSettings(printing::PrinterQuery::DEFAULTS,
-                             NULL,
-                             0,
-                             false,
-                             printing::DEFAULT_MARGINS,
-                             task);
+  printer_query->GetSettings(
+      printing::PrinterQuery::DEFAULTS, NULL, 0, false,
+      printing::DEFAULT_MARGINS,
+      base::Bind(&PrintingMessageFilter::OnGetDefaultPrintSettingsReply, this,
+                 printer_query, reply_msg));
 }
 
 void PrintingMessageFilter::OnGetDefaultPrintSettingsReply(
@@ -236,18 +230,11 @@ void PrintingMessageFilter::OnScriptedPrint(
     printer_query = new printing::PrinterQuery;
   }
 
-  CancelableTask* task = NewRunnableMethod(
-      this,
-      &PrintingMessageFilter::OnScriptedPrintReply,
-      printer_query,
-      reply_msg);
-
-  printer_query->GetSettings(printing::PrinterQuery::ASK_USER,
-                             host_view,
-                             params.expected_pages_count,
-                             params.has_selection,
-                             params.margin_type,
-                             task);
+  printer_query->GetSettings(
+      printing::PrinterQuery::ASK_USER, host_view, params.expected_pages_count,
+      params.has_selection, params.margin_type,
+      base::Bind(&PrintingMessageFilter::OnScriptedPrintReply, this,
+                 printer_query, reply_msg));
 }
 
 void PrintingMessageFilter::OnScriptedPrintReply(
@@ -285,12 +272,11 @@ void PrintingMessageFilter::OnUpdatePrintSettings(
   print_job_manager_->PopPrinterQuery(document_cookie, &printer_query);
   if (!printer_query.get())
     printer_query = new printing::PrinterQuery;
-  CancelableTask* task = NewRunnableMethod(
-      this,
-      &PrintingMessageFilter::OnUpdatePrintSettingsReply,
-      printer_query,
-      reply_msg);
-  printer_query->SetSettings(job_settings, task);
+
+  printer_query->SetSettings(
+      job_settings,
+      base::Bind(&PrintingMessageFilter::OnUpdatePrintSettingsReply, this,
+                 printer_query, reply_msg));
 }
 
 void PrintingMessageFilter::OnUpdatePrintSettingsReply(