Created a new BrowserMessageFilter to handle print related IPC messages.

content/browser/renderer_host/printing_message_filter.h

Index: content/browser/renderer_host/printing_message_filter.h
diff --git a/content/browser/renderer_host/printing_message_filter.h b/content/browser/renderer_host/printing_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..a01a2c0369a8d70bc573e723e203a6583b357d10
--- /dev/null
+++ b/content/browser/renderer_host/printing_message_filter.h
@@ -0,0 +1,80 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.

[jam, 2011/02/22 20:29:41]

all these files should be in chrome\browser\printing

[kmadhusu, 2011/02/23 02:27:49]

Done.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_PRINTING_MESSAGE_FILTER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_PRINTING_MESSAGE_FILTER_H_
+#pragma once
+
+#include "base/shared_memory.h"
+#include "chrome/browser/browser_message_filter.h"
+
+namespace printing {
+class PrinterQuery;
+class PrintJobManager;
+}
+
+struct ViewHostMsg_ScriptedPrint_Params;

[Lei Zhang, 2011/02/22 19:37:42]

nit: this forward decl. should be above the forward decl. in namespaces.

[kmadhusu, 2011/02/23 02:27:49]

Done.

+
+// This class filters out incoming printing related IPC messages for the
+// renderer process on the IPC thread.
+class PrintingMessageFilter : public BrowserMessageFilter {
+ public:
+  PrintingMessageFilter();
+
+  // BrowserMessageFilter methods.
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok);
+
+ private:
+  virtual ~PrintingMessageFilter();
+
+#if defined(OS_POSIX)
+  // Used to ask the browser to allocate a block of shared memory for the
+  // renderer to send back data in, since shared memory can't be created
+  // in the renderer on POSIX due to the sandbox.
+  void OnAllocateSharedMemoryBuffer(uint32 buffer_size,
+                                    base::SharedMemoryHandle* handle);
+#endif
+
+#if defined(OS_WIN)
+  // Used to pass resulting EMF from renderer to browser in printing.
+  void OnDuplicateSection(base::SharedMemoryHandle renderer_handle,
+                          base::SharedMemoryHandle* browser_handle);
+#endif
+
+#if defined(OS_CHROMEOS)
+  // Used to ask the browser allocate a temporary file for the renderer
+  // to fill in resulting PDF in renderer.
+  void OnAllocateTempFileForPrinting(IPC::Message* reply_msg);
+  void OnTempFileForPrintingWritten(int sequence_number);
+  void DoOnAllocateTempFileForPrinting(IPC::Message* reply_msg);

[kmadhusu, 2011/02/21 21:30:04]

Previously, the following functions are declared under the preprocessor USE_X11
but defined under the preprocessor OS_CHROMEOS. Therefore, I declared the
function under "OS_CHROMEOS"
 
  void DoOnAllocateTempFileForPrinting(IPC::Message* reply_msg);
  void DoOnTempFileForPrintingWritten(int sequence_number);

[Lei Zhang, 2011/02/22 19:37:42]

SGTM

+  void DoOnTempFileForPrintingWritten(int sequence_number);
+#endif
+
+  // A javascript code requested to print the current page. This is done in two
+  // steps and this is the first step. Get the print setting right here
+  // synchronously. It will hang the I/O completely.
+  void OnGetDefaultPrintSettings(IPC::Message* reply_msg);
+  void OnGetDefaultPrintSettingsReply(
+      scoped_refptr<printing::PrinterQuery> printer_query,
+      IPC::Message* reply_msg);
+
+  // A javascript code requested to print the current page. The renderer host
+  // have to show to the user the print dialog and returns the selected print
+  // settings.
+  void OnScriptedPrint(const ViewHostMsg_ScriptedPrint_Params& params,
+                       IPC::Message* reply_msg);
+  void OnScriptedPrintReply(
+      scoped_refptr<printing::PrinterQuery> printer_query,
+      int routing_id,
+      IPC::Message* reply_msg);
+
+  printing::PrintJobManager* print_job_manager_;
+
+  bool cloud_print_enabled_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrintingMessageFilter);
+};
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_PRINTING_MESSAGE_FILTER_H_