Fix crashes due to evaluation order

Due to unspecified function argument evaluation order in C++ some
compilers might choose to evaluate base::Passed earlier than subsequent
smart pointer access, so we need to be extra careful and save raw
pointer values before using them. Otherwise they might no longer be
valid by the time we call ptr.get due to the pointer being already
modified by the base::Passed.

BUG=734325

Change-Id: Icb5a06c42c14018c98ab8ddaffcc1fd41f3111ab
Reviewed-on: https://chromium-review.googlesource.com/885091Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Commit-Queue: Sergey Volk <servolk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532704}

extensions/browser/api/networking_private/networking_private_linux.cc

@@ -210,11 +210,14 @@ void NetworkingPrivateLinux::GetState(
       new base::DictionaryValue);
 
   // Runs GetCachedNetworkProperties on |dbus_thread|.
+  std::string* error_ptr = error.get();
+  base::DictionaryValue* network_prop_ptr = network_properties.get();
   dbus_thread_.task_runner()->PostTaskAndReply(
-      FROM_HERE, base::Bind(&NetworkingPrivateLinux::GetCachedNetworkProperties,
+      FROM_HERE,
+      base::Bind(&NetworkingPrivateLinux::GetCachedNetworkProperties,
                  base::Unretained(this), guid,
-                            base::Unretained(network_properties.get()),
-                            base::Unretained(error.get())),
+                 base::Unretained(network_prop_ptr),
+                 base::Unretained(error_ptr)),
       base::Bind(&GetCachedNetworkPropertiesCallback, base::Passed(&error),
                  base::Passed(&network_properties), success_callback,
                  failure_callback));
@@ -297,11 +300,12 @@ void NetworkingPrivateLinux::GetNetworks(
 
   // Runs GetAllWiFiAccessPoints on the dbus_thread and returns the
   // results back to OnAccessPointsFound where the callback is fired.
+  NetworkMap* network_map_ptr = network_map.get();
   dbus_thread_.task_runner()->PostTaskAndReply(
       FROM_HERE,
       base::Bind(&NetworkingPrivateLinux::GetAllWiFiAccessPoints,
                  base::Unretained(this), configured_only, visible_only, limit,
-                 base::Unretained(network_map.get())),
+                 base::Unretained(network_map_ptr)),
       base::Bind(&NetworkingPrivateLinux::OnAccessPointsFound,
                  base::Unretained(this), base::Passed(&network_map),
                  success_callback, failure_callback));
@@ -317,11 +321,13 @@ bool NetworkingPrivateLinux::GetNetworksForScanRequest() {
   // Runs GetAllWiFiAccessPoints on the dbus_thread and returns the
   // results back to SendNetworkListChangedEvent to fire the event. No
   // callbacks are used in this case.
+  NetworkMap* network_map_ptr = network_map.get();
   dbus_thread_.task_runner()->PostTaskAndReply(
-      FROM_HERE, base::Bind(&NetworkingPrivateLinux::GetAllWiFiAccessPoints,
+      FROM_HERE,
+      base::Bind(&NetworkingPrivateLinux::GetAllWiFiAccessPoints,
                  base::Unretained(this), false /* configured_only */,
                  false /* visible_only */, 0 /* limit */,
-                            base::Unretained(network_map.get())),
+                 base::Unretained(network_map_ptr)),
       base::Bind(&NetworkingPrivateLinux::OnAccessPointsFoundViaScan,
                  base::Unretained(this), base::Passed(&network_map)));
 
@@ -503,10 +509,11 @@ void NetworkingPrivateLinux::StartConnect(
   std::unique_ptr<std::string> error(new std::string);
 
   // Runs ConnectToNetwork on |dbus_thread|.
+  std::string* error_ptr = error.get();
   dbus_thread_.task_runner()->PostTaskAndReply(
       FROM_HERE,
       base::Bind(&NetworkingPrivateLinux::ConnectToNetwork,
-                 base::Unretained(this), guid, base::Unretained(error.get())),
+                 base::Unretained(this), guid, base::Unretained(error_ptr)),
       base::Bind(&OnNetworkConnectOperationCompleted, base::Passed(&error),
                  success_callback, failure_callback));
 }
@@ -521,10 +528,11 @@ void NetworkingPrivateLinux::StartDisconnect(
   std::unique_ptr<std::string> error(new std::string);
 
   // Runs DisconnectFromNetwork on |dbus_thread|.
+  std::string* error_ptr = error.get();
   dbus_thread_.task_runner()->PostTaskAndReply(
       FROM_HERE,
       base::Bind(&NetworkingPrivateLinux::DisconnectFromNetwork,
-                 base::Unretained(this), guid, base::Unretained(error.get())),
+                 base::Unretained(this), guid, base::Unretained(error_ptr)),
       base::Bind(&OnNetworkConnectOperationCompleted, base::Passed(&error),
                  success_callback, failure_callback));
 }