[Print Preview]: Added code to support pdf fit to page functionality.

chrome/renderer/print_web_view_helper.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.
 
 #ifndef CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 #define CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 #pragma once
 
 #include <vector>
 
@@ skipping 142 matching lines @@
       const printing::PageSizeMargins& page_layout_in_points,
       gfx::Size* page_size,
       gfx::Rect* content_area);
 
   // Update |ignore_css_margins_| based on settings.
   void UpdateFrameMarginsCssInfo(const base::DictionaryValue& settings);
 
   // Returns true if the current destination printer is PRINT_TO_PDF.
   bool IsPrintToPdfRequested(const base::DictionaryValue& settings);
 
+  // Updates |settings| fit to page information based on |job_settings| and

[Lei Zhang, 2012/04/26 22:52:23]

I think this comment can use some improvements to be less vague.

As an example, the following comment is useless. I cannot tell what this
function is suppose to do without reading the implementation. Even then, I don't
know if the implementation is doing what it is designed to do.

// Returns a value based on |a| and |b|.
int MagicalMathFunction(a, b);

Compare with the following. Here, I know exactly what the function does, and I
can even verify the implementation is correct.

// Returns the largest prime number between |a| and |b|.
int MagicalMathFunction(a, b);

[kmadhusu, 2012/04/27 01:28:58]

As we discussed, I have listed the details and changed the function signature to
return a bool. 

+  // |settings|.
+  void UpdateFitToPageInfo(WebKit::WebFrame* frame,
+                           const WebKit::WebNode& node,
+                           const base::DictionaryValue& job_settings,
+                           PrintMsg_PrintPages_Params* settings);
+
   // Initiate print preview.
   void OnInitiatePrintPreview();
 
   // Start the process of generating a print preview using |settings|.
   void OnPrintPreview(const base::DictionaryValue& settings);
 
   // Initialize the print preview document.
   bool CreatePreviewDocument();
 
   // Renders a print preview page. |page_number| is 0-based.
@@ skipping 294 matching lines @@
     enum PrintPreviewErrorBuckets error_;
 
     State state_;
   };
 
   PrintPreviewContext print_preview_context_;
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };
 
 #endif  // CHROME_RENDERER_PRINT_WEB_VIEW_HELPER_H_