Add GetUsbKeyCode dev interface for Pepper key events

ppapi/api/ppb_input_event.idl

Index: ppapi/api/ppb_input_event.idl
diff --git a/ppapi/api/ppb_input_event.idl b/ppapi/api/ppb_input_event.idl
index 03d5d70d792c2356d9c968afdc0d62ab48321db7..819e9b0d9841935da80ccefaa0da5d85bc13a631 100644
--- a/ppapi/api/ppb_input_event.idl
+++ b/ppapi/api/ppb_input_event.idl
@@ -682,6 +682,9 @@ interface PPB_KeyboardInputEvent {
    * <code>keyCode</code> field. Chrome populates this with the Windows-style
    * Virtual Key code of the key.
    *
+   * @param[in] usb_scan_code This value reflects the USB scancode that
+   * generated this keyboard event.
+   *
    * @param[in] character_text This value represents the typed character as a
    * UTF-8 string.
    *
@@ -693,6 +696,7 @@ interface PPB_KeyboardInputEvent {
                      [in] PP_TimeTicks time_stamp,
                      [in] uint32_t modifiers,
                      [in] uint32_t key_code,
+                     [in] uint32_t usb_scan_code,
                      [in] PP_Var character_text);
 
   /**
@@ -716,6 +720,17 @@ interface PPB_KeyboardInputEvent {
   uint32_t GetKeyCode([in] PP_Resource key_event);
 
   /**
+   * GetUsbScanCode_Dev() returns the USB scancode that corresponds to the key
+   * that generated this keyboard event.
+   *
+   * @param[in] key_event A <code>PP_Resource</code> corresponding to a
+   * keyboard event.
+   *
+   * @return The USB scancode field for the keyboard event.
+   */
+  uint32_t GetUsbScanCode_Dev([in] PP_Resource key_event);

[brettw, 2012/02/09 19:19:44]

We need to keep backwards compat for old users of this interface. You can see
how MouseInputEvent has two versions, 1.1 and 1.0, and two create functions.
You'll also need to set the version on your new function to be 1.1. 

Over IM, I thought we had discussed putting the accessor on a new dev interface.
We don't really have a facility to add dev functions to non-dev interfaces. So
either I would make a separate interface in the dev directory, or leave off the
_Dev for this name (knowing that we're committing to supporting the function).

[Wez, 2012/02/16 19:18:51]

Yes, the plan is to have a new dev interface with a single accessor that takes
an input-event PP_Resource and returns the USB-style key code.  This patch-set
pre-dates our IM, and deals more with the plumbing side of things.

Gary: Is the new patch-set almost ready for review?

[garykac, 2012/02/16 20:45:03]

Patchset 5 and beyond have the updated code (where there's a separate dev
interface that contain the USB accessors).

+
+  /**
    * GetCharacterText() returns the typed character as a UTF-8 string for the
    * given character event.
    *