Implement serial API for Windows.

chrome/browser/extensions/api/serial/serial_apitest.cc

Index: chrome/browser/extensions/api/serial/serial_apitest.cc
diff --git a/chrome/browser/extensions/api/serial/serial_apitest.cc b/chrome/browser/extensions/api/serial/serial_apitest.cc
index 3074c0d7f5dfa3b2c8d0185d22805900c1db396a..83c45df0429da5f2c313fc11d694bcc024b26da1 100644
--- a/chrome/browser/extensions/api/serial/serial_apitest.cc
+++ b/chrome/browser/extensions/api/serial/serial_apitest.cc
@@ -33,15 +33,16 @@ IN_PROC_BROWSER_TEST_F(SerialApiTest, SerialExtension) {
 #if 0
   // Enable this path only if all the following are true:
   //
-  // 1. You're running Linux.
+  // 1. You have an Adafruit Atmega32u4 Breakout Board attached to your machine
+  // and properly appearing as the first virtual serial port ("first" is very
+  // loosely defined as whichever port shows up in serial.getPorts). Other
+  // devices will work, but this is the only one tested.
   //
-  // 2. You have an Adafruit ATmega32u4 breakout board attached to your machine
-  // via USB with the Arduino Leonardo bootloader flashed to the board. Other
-  // devices will work; this is the only one tested.
+  // 2. Your user has permission to read/write the port. For example, this might
+  // mean that your user is in the "tty" group on Ubuntu flavors of Linux, or
+  // else that /dev/ttyACM0 has global read/write permissions.
   //
-  // 3. Your user has permission to read/write the /dev/ttyACM0 device.
-  //
-  // 4. You have uploaded a program to the '32u4 that does a byte-for-byte echo
+  // 4. You have uploaded a program to the board that does a byte-for-byte echo
   // on the virtual serial port at 57600 bps. Here is an example (built using
   // the Arduino IDE):
   //
@@ -56,12 +57,9 @@ IN_PROC_BROWSER_TEST_F(SerialApiTest, SerialExtension) {
   //     }
   //   }
   // }
-  //
-  // TODO(miket): Enable a more forgiving set of test conditions, specifically
-  // by mocking SerialConnection.
-  listener.Reply("/dev/ttyACM0");
+  listener.Reply("echo_device_attached");
 #else
-  listener.Reply("none");
+  listener.Reply("false");
 #endif
 
   EXPECT_TRUE(catcher.GetNextResult()) << catcher.message();