Cleanup code in printing/

- Use stdint.h types.
- Fix lint errors.

Review URL: https://codereview.chromium.org/1343593002

Cr-Commit-Position: refs/heads/master@{#348660}
diff --git a/printing/print_settings_initializer_mac.cc b/printing/print_settings_initializer_mac.cc
index 7dc41a6..926d6988 100644
--- a/printing/print_settings_initializer_mac.cc
+++ b/printing/print_settings_initializer_mac.cc
@@ -28,7 +28,7 @@
                                                        &resolution_count);
   if (status == noErr) {
     // Resolution indexes are 1-based.
-    for (uint32 i = 1; i <= resolution_count; ++i) {
+    for (uint32_t i = 1; i <= resolution_count; ++i) {
       PMResolution resolution;
       PMPrinterGetIndexedPrinterResolution(printer, i, &resolution);
       if (resolution.hRes > best_resolution.hRes)