Implement window.print() on Android

chrome/common/print_messages.h

 // 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.
 
 // IPC messages for printing.
 // Multiply-included message file, hence no include guard.
 
 #include <string>
 #include <vector>
 
@@ skipping 281 matching lines @@
 
   // The printable area the page author specified.
   IPC_STRUCT_MEMBER(gfx::Rect, content_area)
 IPC_STRUCT_END()
 
 // Parameters for the IPC message ViewHostMsg_ScriptedPrint
 IPC_STRUCT_BEGIN(PrintHostMsg_ScriptedPrint_Params)
   IPC_STRUCT_MEMBER(int, cookie)
   IPC_STRUCT_MEMBER(int, expected_pages_count)
   IPC_STRUCT_MEMBER(bool, has_selection)
+  IPC_STRUCT_MEMBER(bool, use_system_specific_flow)
   IPC_STRUCT_MEMBER(printing::MarginType, margin_type)
 IPC_STRUCT_END()
 
 
 // Messages sent from the browser to the renderer.
 
 // Tells the render view to initiate print preview for the entire document.
 IPC_MESSAGE_ROUTED1(PrintMsg_InitiatePrintPreview, bool /* selection_only */)
 
 // Tells the render frame to initiate printing or print preview for a particular
@@ skipping 155 matching lines @@
 IPC_SYNC_MESSAGE_ROUTED0_0(PrintHostMsg_SetupScriptedPrintPreview)
 
 // Tell the browser to show the print preview, when the document is sufficiently
 // loaded such that the renderer can determine whether it is modifiable or not.
 IPC_MESSAGE_ROUTED1(PrintHostMsg_ShowScriptedPrintPreview,
                     bool /* is_modifiable */)
 
 // Notify the browser to set print presets based on source PDF document.
 IPC_MESSAGE_ROUTED1(PrintHostMsg_SetOptionsFromDocument,
                     PrintHostMsg_SetOptionsFromDocument_Params /* params */)