Implement window.print() on Android

chrome/browser/printing/print_job_worker.h

Index: chrome/browser/printing/print_job_worker.h
diff --git a/chrome/browser/printing/print_job_worker.h b/chrome/browser/printing/print_job_worker.h
index a8378bb2353de2cd98746c087bfb5e02a595bba6..a8a8185612c2e007342e8d379a90ee0d5872e2bf 100644
--- a/chrome/browser/printing/print_job_worker.h
+++ b/chrome/browser/printing/print_job_worker.h
@@ -39,10 +39,12 @@ class PrintJobWorker {
 
   void SetNewOwner(PrintJobWorkerOwner* new_owner);
 
-  // Initializes the print settings. If |ask_user_for_settings| is true, a
-  // Print... dialog box will be shown to ask the user his preference.
+  // Initializes the print settings. If |ask_settings_type| is ASK_USER, a
+  // Print... dialog box will be shown by the browser to ask the user his
+  // preference. If it is SYSTEM_SPECIFIC, showing that dialog box will be

[mlamouri (slow - plz ping), 2014/11/27 20:26:02]

I do not understand why this is needed.

[dgn, 2014/11/28 11:51:15]

Updated the comment. I tried to address that in more in depth in the CL
description. 

+  // delegated to the system.
   void GetSettings(
-      bool ask_user_for_settings,
+      GetSettingsAskParam ask_settings_type,
       int document_page_count,
       bool has_selection,
       MarginType margin_type);
@@ -115,6 +117,9 @@ class PrintJobWorker {
   // back into the IO thread for GetSettingsDone().
   void GetSettingsWithUIDone(PrintingContext::Result result);
 
+  // Called on the UI thread to ask the system to show a print dialog.
+  void ShowSystemDialog();
+
   // Called on the UI thread to update the print settings.
   void UpdatePrintSettings(scoped_ptr<base::DictionaryValue> new_settings);