Adding basic Metro Print Metrics.

printing/printing_context_win.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "printing/printing_context_win.h"
 
 #include <winspool.h>
 
 #include <algorithm>
 
 #include "base/i18n/file_util_icu.h"
 #include "base/i18n/time_formatting.h"
 #include "base/message_loop.h"
+#include "base/metrics/histogram.h"
 #include "base/time.h"
 #include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "base/win/metro.h"
 #include "printing/backend/win_helper.h"
 #include "printing/print_job_constants.h"
 #include "printing/print_settings_initializer_win.h"
 #include "printing/printed_document.h"
 #include "printing/units.h"
 #include "skia/ext/platform_device.h"
@@ skipping 199 matching lines @@
 
   if (base::win::IsMetroProcess()) {
     // The system dialog can not be opened while running in Metro.
     // But we can programatically launch the Metro print device charm though.
     HMODULE metro_module = base::win::GetMetroModule();
     if (metro_module != NULL) {
       typedef void (*MetroShowPrintUI)();
       MetroShowPrintUI metro_show_print_ui =
           reinterpret_cast<MetroShowPrintUI>(
               ::GetProcAddress(metro_module, "MetroShowPrintUI"));
-      if (metro_show_print_ui)
+      if (metro_show_print_ui) {
+        // TODO(mad): Remove this once we can send user metrics from the metro
+        // driver. crbug.com/142330
+        UMA_HISTOGRAM_ENUMERATION("Metro.Print", 1, 2);

[Ilya Sherman, 2012/08/13 22:34:00]

nit: I recommend having a single location in the codebase that logs any given
histogram.  Typically, I've seen people create small utility
header+implementation files for this purpose.  The advantages are (1) it's much
less likely that you'll accidentally name the histogram differently in different
call sites due to a typo; (2) you can't forget to update one of the call sites
when updating the histogram; and (3) Jim tells me we end up with slightly better
compiled code if there's only one definition for each histogram (this last
reason is pretty minor though).

         metro_show_print_ui();
+      }
     }
     return callback.Run(CANCEL);
   }
   dialog_box_dismissed_ = false;
 
   HWND window;
   if (!view || !IsWindow(view)) {
     // TODO(maruel):  bug 1214347 Get the right browser window instead.
     window = GetDesktopWindow();
   } else {
@@ skipping 568 matching lines @@
   if (buf_size) {
     buffer->reset(new uint8[buf_size]);
     memset(buffer->get(), 0, buf_size);
     if (!GetPrinter(printer, level, buffer->get(), buf_size, &buf_size)) {
       buffer->reset();
     }
   }
 }
 
 }  // namespace printing