Binary Size tool: Check DWARF format only when possible.

tools/binary_size/run_binary_size_analysis.py

 #!/usr/bin/env python
 # Copyright 2014 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.
 
 """Generate a spatial analysis against an arbitrary library.
 
 To use, build the 'binary_size_tool' target. Then run this tool, passing
 in the location of the library to be analyzed along with any other options
 you desire.
@@ skipping 852 matching lines @@
     nm_binary = _find_in_system_path('nm')
     assert nm_binary, 'Unable to find nm in the path. Use --nm-binary '\
         'to specify location.'
 
   if opts.pak:
     assert os.path.isfile(opts.pak), 'Could not find ' % opts.pak
 
   print('addr2line: %s' % addr2line_binary)
   print('nm: %s' % nm_binary)
 
-  CheckDebugFormatSupport(opts.library, addr2line_binary)
+  if opts.library:
+    CheckDebugFormatSupport(opts.library, addr2line_binary)
 
   symbols = GetNmSymbols(opts.nm_in, opts.nm_out, opts.library,
                          opts.jobs, opts.verbose is True,
                          addr2line_binary, nm_binary,
                          opts.disable_disambiguation is None,
                          opts.source_path)
 
   if opts.pak:
     AddPakData(symbols, opts.pak)
 
@@ skipping 38 matching lines @@
     shutil.copy(os.path.join(d3_src, 'LICENSE'), d3_out)
     shutil.copy(os.path.join(d3_src, 'd3.js'), d3_out)
     shutil.copy(os.path.join(template_src, 'index.html'), opts.destdir)
     shutil.copy(os.path.join(template_src, 'D3SymbolTreeMap.js'), opts.destdir)
 
   print 'Report saved to ' + opts.destdir + '/index.html'
 
 
 if __name__ == '__main__':
   sys.exit(main())