Add "create_bundle" target in order to support bundle with gn.

tools/gn/create_bundle_target_generator.cc

Index: tools/gn/create_bundle_target_generator.cc
diff --git a/tools/gn/create_bundle_target_generator.cc b/tools/gn/create_bundle_target_generator.cc
new file mode 100644
index 0000000000000000000000000000000000000000..dbc58fc77e78f8fbf385f4c4496037f9fd293f1c
--- /dev/null
+++ b/tools/gn/create_bundle_target_generator.cc
@@ -0,0 +1,68 @@
+// Copyright 2016 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.
+
+#include "tools/gn/create_bundle_target_generator.h"
+
+#include "tools/gn/filesystem_utils.h"
+#include "tools/gn/parse_tree.h"
+#include "tools/gn/scope.h"
+#include "tools/gn/substitution_type.h"
+#include "tools/gn/target.h"
+#include "tools/gn/value.h"
+#include "tools/gn/variables.h"
+
+CreateBundleTargetGenerator::CreateBundleTargetGenerator(
+    Target* target,
+    Scope* scope,
+    const FunctionCallNode* function_call,
+    Err* err) : TargetGenerator(target, scope, function_call, err) {}
+
+CreateBundleTargetGenerator::~CreateBundleTargetGenerator() {}
+
+void CreateBundleTargetGenerator::DoRun() {
+  target_->set_output_type(Target::CREATE_BUNDLE);
+
+  BundleData& bundle_data = target_->bundle_data();
+  if (!GetBundleDir(std::string(),
+                    variables::kBundleRootDir,
+                    &bundle_data.root_dir()))
+    return;
+  if (!GetBundleDir(bundle_data.root_dir(),
+                    variables::kBundleResourcesDir,
+                    &bundle_data.resources_dir()))
+    return;
+  if (!GetBundleDir(bundle_data.root_dir(),
+                    variables::kBundleExecutableDir,
+                    &bundle_data.executable_dir()))
+    return;
+  if (!GetBundleDir(bundle_data.root_dir(),
+                    variables::kBundlePlugInsDir,
+                    &bundle_data.plugins_dir()))
+    return;
+}
+
+bool CreateBundleTargetGenerator::GetBundleDir(
+    const std::string& bundle_root_dir,
+    const base::StringPiece& name,
+    std::string* bundle_dir) {
+  const Value* value = scope_->GetValue(name, true);
+  if (!value)
+    return true;
+  if (!value->VerifyTypeIs(Value::STRING, err_))
+    return false;
+  const std::string& str = value->string_value();
+  if (!EnsureStringIsInOutputDir(GetBuildSettings()->build_dir(),
+      str, value->origin(), err_))
+    return false;
+  if (str != bundle_root_dir &&
+      !IsStringInOutputDir(SourceDir(bundle_root_dir), str)) {
+    *err_ = Err(value->origin(), "Path is not in bundle root dir.",
+        "The given file should be in the bundle root directory or below.\n"
+        "Normally you would do \"$bundle_root_dir/foo\". I interpreted this\n"
+        "as \"" + str + "\".");
+    return false;
+  }
+  bundle_dir->assign(value->string_value());
+  return true;
+}