Printing: Fix undefined behavior for near 0 scaling

components/printing/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 COMPONENTS_PRINTING_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 #define COMPONENTS_PRINTING_RENDERER_PRINT_WEB_VIEW_HELPER_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 94 matching lines @@
 
     // Returns true if printing is overridden and the default behavior should be
     // skipped for |frame|.
     virtual bool OverridePrint(blink::WebLocalFrame* frame) = 0;
   };
 
   PrintWebViewHelper(content::RenderView* render_view,
                      std::unique_ptr<Delegate> delegate);
   ~PrintWebViewHelper() override;
 
+  // Minimum valid value for scaling. Since scaling is originally an integer
+  // representing a percentage, it should never be less than this if it is
+  // valid.
+  static constexpr double kEpsilon = 0.01f;
+
   // Disable print preview and switch to system dialog printing even if full
   // printing is build-in. This method is used by CEF.
   static void DisablePreview();
 
   bool IsPrintingEnabled();
 
   void PrintNode(const blink::WebNode& node);
 
  private:
   friend class PrintWebViewHelperTestBase;
@@ skipping 401 matching lines @@
   base::Closure on_stop_loading_closure_;
 
   base::WeakPtrFactory<PrintWebViewHelper> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PrintWebViewHelper);
 };
 
 }  // namespace printing
 
 #endif  // COMPONENTS_PRINTING_RENDERER_PRINT_WEB_VIEW_HELPER_H_