Improve documentation of the targets generated by mojom.gni.

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 31 matching lines @@
   foreach(typemap, configuration.typemaps) {
     read_file(typemap.mojom, "")
   }
   if (is_mac && defined(configuration.typemaps_mac)) {
     foreach(typemap, configuration.typemaps_mac) {
       read_file(typemap.mojom, "")
     }
   }
 }
 
-# Generate C++/JavaScript/Java source files from mojom files. The output files
-# will go under the generated file directory tree with the same path as each
-# input file.
+# Generates targets for building C++, JavaScript and Java bindings from mojom
+# files. The output files will go under the generated file directory tree with
+# the same path as each input file.
+#
+# Other targets should depend on one of these generated targets (where "foo"
+# is the target name):
+#
+#   foo
+#       C++ and Javascript bindings. Other mojom targets should also depend on
+#       this target.
+#
+#   foo_blink
+#       C++ bindings using Blink standard types.
+#
+#   foo_java
+#       Java bindings.
 #
 # Parameters:
 #
 #   sources (optional if one of the deps sets listed below is present)
 #       List of source .mojom files to compile.
 #
 #   deps (optional)
 #       Note: this can contain only other mojom targets.
 #
 #       DEPRECATED: This is synonymous with public_deps because all mojom
@@ skipping 490 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
       }
     }
   }
 }