app_list: Add web store search.

chrome/browser/safe_json_parser.cc

+// Copyright 2013 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 "chrome/browser/safe_json_parser.h"
+
+#include "chrome/common/chrome_utility_messages.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/utility_process_host.h"
+
+using content::BrowserThread;
+using content::UtilityProcessHost;
+
+SafeJsonParser::SafeJsonParser(const std::string& unsafe_json,
+                               const SuccessCallback& success_callback,
+                               const ErrorCallback& error_callback)
+    : unsafe_json_(unsafe_json),
+      success_callback_(success_callback),
+      error_callback_(error_callback) {}
+
+SafeJsonParser::~SafeJsonParser() {}
+
+void SafeJsonParser::Start() {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));

[James Cook, 2013/05/20 14:39:34]

Could the thread assertions be DCHECKs?

[xiyuan, 2013/05/20 16:56:31]

Done. Thread assertions are changed to use DCHECKs.

+  BrowserThread::PostTask(
+      BrowserThread::IO,
+      FROM_HERE,
+      base::Bind(&SafeJsonParser::StartWorkOnIOThread, this));
+}
+
+void SafeJsonParser::StartWorkOnIOThread() {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  UtilityProcessHost* host =
+      UtilityProcessHost::Create(
+          this, base::MessageLoopProxy::current());
+  host->EnableZygote();
+  host->Send(new ChromeUtilityMsg_ParseJSON(unsafe_json_));
+}
+
+void SafeJsonParser::OnJSONParseSucceeded(const base::ListValue& wrapper) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  const Value* value = NULL;
+  CHECK(wrapper.Get(0, &value));
+
+  parsed_json_.reset(value->DeepCopy());
+  ReportResults();
+}
+
+void SafeJsonParser::OnJSONParseFailed(const std::string& error_message) {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+  error_ = error_message;
+  ReportResults();
+}
+
+void SafeJsonParser::ReportResults() {
+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
+
+  BrowserThread::PostTask(
+      BrowserThread::UI,
+      FROM_HERE,
+      base::Bind(&SafeJsonParser::ReportResultOnUIThread, this));
+}
+
+void SafeJsonParser::ReportResultOnUIThread() {

[James Cook, 2013/05/20 14:39:34]

Actually, who deletes this object? The destructor is private.

[xiyuan, 2013/05/20 16:56:31]

SafeJsonParser derives from UtilityProcessHostClient, which derives a
RefCountedThreadSafe object. So as long as we have pending PostTasks, the object
is alive. And it will be deleted when all tasks are finished, i.e. after
ReportResultOnUIThread returns.

+  CHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (error_.empty() && parsed_json_) {
+    if (!success_callback_.is_null())
+      success_callback_.Run(parsed_json_.Pass());
+  } else {
+    if (!error_callback_.is_null())
+      error_callback_.Run(error_);
+  }
+}
+
+bool SafeJsonParser::OnMessageReceived(const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(SafeJsonParser, message)
+    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParseJSON_Succeeded,
+                        OnJSONParseSucceeded)
+    IPC_MESSAGE_HANDLER(ChromeUtilityHostMsg_ParseJSON_Failed,
+                        OnJSONParseFailed)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}