Make some fields non-nullable in serial.mojom and data_stream.mojom.

This also removes some null checks for the now non-nullable fields.

BUG=407683

Review URL: https://codereview.chromium.org/562563002

Cr-Commit-Position: refs/heads/master@{#294277}

device/serial/data_sink_receiver.cc

@@ -89,7 +89,7 @@ DataSinkReceiver::~DataSinkReceiver() {
 }
 
 void DataSinkReceiver::Init(mojo::ScopedDataPipeConsumerHandle handle) {
-  if (!handle.is_valid() || handle_.is_valid()) {
+  if (handle_.is_valid()) {
     DispatchFatalError();
     return;
   }

device/serial/data_source_sender.cc

@@ -90,9 +90,8 @@ DataSourceSender::~DataSourceSender() {
 
 void DataSourceSender::Init(mojo::ScopedDataPipeProducerHandle handle) {
   // This should never occur. |handle_| is only valid and |pending_send_| is
-  // only set after Init is called. Receiving an invalid |handle| from the
-  // client is also unrecoverable.
-  if (pending_send_ || handle_.is_valid() || !handle.is_valid() || shut_down_) {
+  // only set after Init is called.
+  if (pending_send_ || handle_.is_valid() || shut_down_) {
     DispatchFatalError();
     return;
   }

device/serial/data_stream.mojom

@@ -8,7 +8,7 @@ module device.serial {
 interface DataSource {
   // Initializes this DataSource with a data pipe handle to use for data
   // transmission.
-  Init(handle<data_pipe_producer>? producer_handle);
+  Init(handle<data_pipe_producer> producer_handle);
 
   // Resumes sending data after it has been stopped due to an error.
   Resume();
@@ -25,7 +25,7 @@ interface DataSourceClient {
 interface DataSink {
   // Initializes this DataSink with a data pipe handle to use for data
   // transmission.
-  Init(handle<data_pipe_consumer>? consumer_handle);
+  Init(handle<data_pipe_consumer> consumer_handle);
 
   // Requests the cancellation of any data that has been written to the pipe,
   // but has not yet been sent to the sink.

device/serial/serial.mojom

@@ -7,7 +7,7 @@ import "data_stream.mojom"
 module device.serial {
 
 struct DeviceInfo {
-  string? path;
+  string path;
   uint16 vendor_id;
   bool has_vendor_id = false;
   uint16 product_id;
@@ -82,7 +82,7 @@ struct DeviceControlSignals {
 };
 
 interface SerialService {
-  GetDevices() => (DeviceInfo?[]? devices);
+  GetDevices() => (DeviceInfo[] devices);
 
   // Creates a |Connection| to |path| with options specified by |options|,
   // returning it via |connection|. Sending and receiving data over this
@@ -90,17 +90,17 @@ interface SerialService {
   // and |connection| will not be usable if |path| does not specify a valid
   // serial device or there is an error connecting to or configuring the
   // connection.
-  Connect(string? path,
+  Connect(string path,
           ConnectionOptions? options,
-          Connection&? connection,
-          DataSink&? sink,
-          DataSource&? source);
+          Connection& connection,
+          DataSink& sink,
+          DataSource& source);
 };
 
 interface Connection {
   GetInfo() => (ConnectionInfo? info);
-  SetOptions(ConnectionOptions? options) => (bool success);
-  SetControlSignals(HostControlSignals? signals) => (bool success);
+  SetOptions(ConnectionOptions options) => (bool success);
+  SetControlSignals(HostControlSignals signals) => (bool success);
   GetControlSignals() => (DeviceControlSignals? signals);
   Flush() => (bool success);
 };

extensions/renderer/api/serial/serial_api_unittest.cc

@@ -33,6 +33,7 @@ class FakeSerialDeviceEnumerator : public device::SerialDeviceEnumerator {
     result[1]->vendor_id = 1234;
     result[1]->product_id = 5678;
     result[2] = device::serial::DeviceInfo::New();
+    result[2]->path = "";
     result[2]->display_name = "";
     return result.Pass();
   }

extensions/renderer/resources/serial_service.js

@@ -30,7 +30,7 @@ define('serial_service', [
   function getDevices() {
     return service.getDevices().then(function(response) {
       return $Array.map(response.devices, function(device) {
-        var result = {path: device.path || ''};
+        var result = {path: device.path};
         if (device.has_vendor_id)
           result.vendorId = device.vendor_id;
         if (device.has_product_id)