Generate param traits size methods for IPC files in content/ (and traits it depends on).

mojo/public/tools/bindings/mojom.gni

 # 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.
 
 mojom_generator_root = "//mojo/public/tools/bindings"
 mojom_generator_script = "$mojom_generator_root/mojom_bindings_generator.py"
 mojom_generator_sources = [
   "$mojom_generator_root/generators/mojom_cpp_generator.py",
   "$mojom_generator_root/generators/mojom_js_generator.py",
   "$mojom_generator_root/generators/mojom_java_generator.py",
@@ skipping 194 matching lines @@
         ]
 
         if (defined(bindings_configuration.for_blink) &&
             bindings_configuration.for_blink) {
           args += [ "--for_blink" ]
         }
       }
     }
 
     action(type_mappings_target_name) {
+      inputs = _bindings_configuration_files

[jam, 2016/05/11 15:27:24]

fix per rockot so that gen\content\common\mojo_bindings__type_mappings is
regenerated when mojo/public/tools/bindings/chromium_bindings_configuration.gni
changes

       outputs = [
         type_mappings_path,
       ]
       script = "$mojom_generator_root/generate_type_mappings.py"
       deps = []
       args = [
         "--output",
         rebase_path(type_mappings_path, root_build_dir),
       ]
 
@@ skipping 161 matching lines @@
           full_name = get_label_info(d, "label_no_toolchain")
           deps += [ "${full_name}_java" ]
         }
 
         srcjar_deps = [ ":$java_srcjar_target_name" ]
         run_findbugs_override = false
       }
     }
   }
 }