Fix assigning NULL to scoped_refptr

Update code where NULL or 0 is assigned to a scoped_refptr to reset it. Just
call reset() instead. If operator=(std::nullptr_t) is added these assignments
become ambiguous.

This CL was uploaded by git cl split.

R=reillyg@chromium.org

Bug: 1024981
Change-Id: I11e16eb6457e3de133bf6528b437f0753e73b5ce
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1918322
Auto-Submit: kylechar <kylechar@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Commit-Queue: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#715485}

extensions/browser/api/bluetooth_low_energy/bluetooth_low_energy_event_router.cc

@@ -267,7 +267,7 @@ BluetoothLowEnergyEventRouter::~BluetoothLowEnergyEventRouter() {
   }
 
   adapter_->RemoveObserver(this);
-  adapter_ = NULL;
+  adapter_.reset();
 }
 
 bool BluetoothLowEnergyEventRouter::IsBluetoothSupported() const {

extensions/browser/api/declarative/rules_registry_unittest.cc

@@ -145,7 +145,7 @@ TEST(RulesRegistryTest, FillOptionalIdentifiers) {
             registry->GetNumberOfUsedRuleIdentifiersForTesting());
 
   // Make sure that deletion traits of registry are executed.
-  registry = NULL;
+  registry.reset();
   base::RunLoop().RunUntilIdle();
 }
 
@@ -182,7 +182,7 @@ TEST(RulesRegistryTest, FillOptionalPriority) {
             std::max(*get_rules[0]->priority, *get_rules[1]->priority));
 
   // Make sure that deletion traits of registry are executed.
-  registry = NULL;
+  registry.reset();
   base::RunLoop().RunUntilIdle();
 }
 

extensions/browser/api/display_source/display_source_apitestbase.cc

@@ -519,7 +519,7 @@ void MockDisplaySourceConnectionDelegate::OnMediaPacketReceived(
     int net_result) {
   DCHECK_CURRENTLY_ON(BrowserThread::IO);
   DCHECK(recvfrom_buffer_.get());
-  recvfrom_buffer_ = NULL;
+  recvfrom_buffer_.reset();
 
   if (net_result > 0) {
     // We received at least one media packet.

extensions/browser/api/socket/socket.cc

@@ -64,7 +64,7 @@ void Socket::WriteData() {
 }
 
 void Socket::OnWriteComplete(int result) {
-  io_buffer_write_ = NULL;
+  io_buffer_write_.reset();
 
   WriteRequest& request = write_queue_.front();
 

extensions/browser/info_map_unittest.cc

@@ -51,7 +51,7 @@ TEST_F(InfoMapTest, RefCounting) {
 
   // Release extension1, and the info map should have the only ref.
   const Extension* weak_extension1 = extension1.get();
-  extension1 = NULL;
+  extension1.reset();
   EXPECT_TRUE(weak_extension1->HasOneRef());
 
   // Remove extension2, and the extension2 object should have the only ref.
@@ -60,7 +60,7 @@ TEST_F(InfoMapTest, RefCounting) {
   EXPECT_TRUE(extension2->HasOneRef());
 
   // Delete the info map, and the extension3 object should have the only ref.
-  info_map = NULL;
+  info_map.reset();
   EXPECT_TRUE(extension3->HasOneRef());
 }
 

extensions/browser/sandboxed_unpacker.cc

@@ -938,7 +938,7 @@ void SandboxedUnpacker::ReportSuccess(
   client_->OnUnpackSuccess(temp_dir_.Take(), extension_root_,
                            std::move(original_manifest), extension_.get(),
                            install_icon_, dnr_ruleset_checksum);
-  extension_ = NULL;
+  extension_.reset();
 
   Cleanup();
 }

extensions/test/extension_test_message_listener.cc

@@ -55,7 +55,7 @@ void ExtensionTestMessageListener::Reply(const std::string& message) {
 
   replied_ = true;
   function_->Reply(message);
-  function_ = NULL;
+  function_.reset();
 }
 
 void ExtensionTestMessageListener::Reply(int message) {
@@ -68,7 +68,7 @@ void ExtensionTestMessageListener::ReplyWithError(const std::string& error) {
 
   replied_ = true;
   function_->ReplyWithError(error);
-  function_ = NULL;
+  function_.reset();
 }
 
 void ExtensionTestMessageListener::Reset() {