Ensure that the on screen keyboard detection on Windows 8+ is more reliable.

The keyboard detection code is heuristic based as we don't have a reliable way to detect if a keyboard
is attached. We use the Setup API's for keyboard class GUID's and look for specific prefixes in the device names like
ACPI\PNP*, ACPI\MSF* and HID\VID*. If we find one of these we assume that a keyboard is present.

Fixed a bug in the keyboard detection function where in the order of params for the StartsWith helper was flipped.

This works on the Surface and Samsung touch screen laptops in my testing.

BUG=335735

Review URL: https://codereview.chromium.org/969293002

Cr-Commit-Position: refs/heads/master@{#318961}

base/win/win_util.cc

@@ -57,7 +57,7 @@ const wchar_t kWindows8OSKRegPath[] =
 
 // Returns true if a physical keyboard is detected on Windows 8 and up.
 // Uses the Setup APIs to enumerate the attached keyboards and returns true
-// if the keyboard count is more than 1. While this will work in most cases
+// if the keyboard count is 1 or more.. While this will work in most cases
 // it won't work if there are devices which expose keyboard interfaces which
 // are attached to the machine.
 bool IsKeyboardPresentOnSlate() {
@@ -89,6 +89,7 @@ bool IsKeyboardPresentOnSlate() {
     device_info_data.cbSize = sizeof(device_info_data);
     if (!SetupDiEnumDeviceInfo(device_info, i, &device_info_data))
       break;
+
     // Get the device ID.
     wchar_t device_id[MAX_DEVICE_ID_LEN];
     CONFIGRET status = CM_Get_Device_ID(device_info_data.DevInst,
@@ -96,20 +97,19 @@ bool IsKeyboardPresentOnSlate() {
                                         MAX_DEVICE_ID_LEN,
                                         0);
     if (status == CR_SUCCESS) {
-      // To reduce the scope of the hack we only look for PNP and HID
+      // To reduce the scope of the hack we only look for PNP, MSF and HID
       // keyboards.
-      if (StartsWith(L"ACPI\\PNP", device_id, false) ||
-          StartsWith(L"HID\\VID", device_id, false)) {
+      if (StartsWith(device_id, L"ACPI\\PNP", false) ||
+          StartsWith(device_id, L"ACPI\\MSF", false) ||
+          StartsWith(device_id, L"HID\\VID", false)) {
         keyboard_count++;
       }
     }
   }
-  // On a Windows machine, the API's always report 1 keyboard at least
-  // regardless of whether the machine has a keyboard attached or not.
-  // The heuristic we are using is to check the count and return true
-  // if the API's report more than one keyboard. Please note that this
+  // The heuristic we are using is to check the count of keyboards and return
+  // true if the API's report one or more keyboards. Please note that this
   // will break for non keyboard devices which expose a keyboard PDO.
-  return keyboard_count > 1;
+  return keyboard_count >= 1;
 }
 
 }  // namespace