Revert 203489 "Replace JSON (de)serialization of extension messa..."

Breaks page_cycler_2012Q2-netsim benchmark.

BUG=246213

> Replace JSON (de)serialization of extension messages with direct Value pickling.
> 
> BUG=55316
> R=mpcomplete@chromium.org
> TBR=cdn@chromium.org
> 
> Review URL: https://chromiumcodereview.appspot.com/16226004

TBR=kalman@chromium.org
NOTRY=True

Review URL: https://codereview.chromium.org/16336011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@203753 0039d316-1c4b-4281-b951-d872f2087c98

20 files changed, 106 insertions, 199 deletions

diff --git a/chrome/browser/extensions/api/messaging/extension_message_port.cc b/chrome/browser/extensions/api/messaging/extension_message_port.cc
index a3bba97..e4782c7 100644
--- a/chrome/browser/extensions/api/messaging/extension_message_port.cc
+++ b/chrome/browser/extensions/api/messaging/extension_message_port.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/extensions/api/messaging/extension_message_port.h"
 
-#include "base/values.h"
 #include "chrome/browser/extensions/extension_host.h"
 #include "chrome/browser/extensions/extension_process_manager.h"
 #include "chrome/browser/extensions/extension_system.h"
@@ -46,11 +45,10 @@ void ExtensionMessagePort::DispatchOnDisconnect(
       routing_id_, source_port_id, error_message));
 }
 
-void ExtensionMessagePort::DispatchOnMessage(
-    scoped_ptr<base::ListValue> message,
-    int target_port_id) {
-  process_->Send(new ExtensionMsg_DeliverMessage(
-      routing_id_, target_port_id, *message));
+void ExtensionMessagePort::DispatchOnMessage(const std::string& message,
+                                             int target_port_id) {
+    process_->Send(new ExtensionMsg_DeliverMessage(
+        routing_id_, target_port_id, message));
 }
 
 void ExtensionMessagePort::IncrementLazyKeepaliveCount() {
diff --git a/chrome/browser/extensions/api/messaging/extension_message_port.h b/chrome/browser/extensions/api/messaging/extension_message_port.h
index 7cc386a..ccf9b69 100644
--- a/chrome/browser/extensions/api/messaging/extension_message_port.h
+++ b/chrome/browser/extensions/api/messaging/extension_message_port.h
@@ -9,10 +9,6 @@
 
 class GURL;
 
-namespace base {
-class ListValue;
-}
-
 namespace content {
 class RenderProcessHost;
 }  // namespace content
@@ -34,7 +30,7 @@ class ExtensionMessagePort : public MessageService::MessagePort {
       const GURL& source_url) OVERRIDE;
   virtual void DispatchOnDisconnect(int source_port_id,
                                     const std::string& error_message) OVERRIDE;
-  virtual void DispatchOnMessage(scoped_ptr<base::ListValue> message,
+  virtual void DispatchOnMessage(const std::string& message,
                                  int target_port_id) OVERRIDE;
   virtual void IncrementLazyKeepaliveCount() OVERRIDE;
   virtual void DecrementLazyKeepaliveCount() OVERRIDE;
diff --git a/chrome/browser/extensions/api/messaging/message_service.cc b/chrome/browser/extensions/api/messaging/message_service.cc
index 3d374b7..169e1b5 100644
--- a/chrome/browser/extensions/api/messaging/message_service.cc
+++ b/chrome/browser/extensions/api/messaging/message_service.cc
@@ -6,7 +6,6 @@
 
 #include "base/atomic_sequence_num.h"
 #include "base/bind.h"
-#include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/json/json_writer.h"
 #include "base/lazy_instance.h"
@@ -430,7 +429,7 @@ void MessageService::CloseChannelImpl(
 }
 
 void MessageService::PostMessage(
-    int source_port_id, scoped_ptr<base::ListValue> message) {
+    int source_port_id, const std::string& message) {
   int channel_id = GET_CHANNEL_ID(source_port_id);
   MessageChannelMap::iterator iter = channels_.find(channel_id);
   if (iter == channels_.end()) {
@@ -441,9 +440,7 @@ void MessageService::PostMessage(
       lazy_background_task_queue_->AddPendingTask(
           pending->second.first, pending->second.second,
           base::Bind(&MessageService::PendingPostMessage,
-                     weak_factory_.GetWeakPtr(),
-                     source_port_id,
-                     base::Passed(&message)));
+                     weak_factory_.GetWeakPtr(), source_port_id, message));
     }
     return;
   }
@@ -453,13 +450,12 @@ void MessageService::PostMessage(
   MessagePort* port = IS_OPENER_PORT_ID(dest_port_id) ?
       iter->second->opener.get() : iter->second->receiver.get();
 
-  port->DispatchOnMessage(message.Pass(), dest_port_id);
+  port->DispatchOnMessage(message, dest_port_id);
 }
 
-void MessageService::PostMessageFromNativeProcess(
-    int port_id,
-    scoped_ptr<base::ListValue> message) {
-  PostMessage(port_id, message.Pass());
+void MessageService::PostMessageFromNativeProcess(int port_id,
+                                                  const std::string& message) {
+  PostMessage(port_id, message);
 }
 
 void MessageService::Observe(int type,
diff --git a/chrome/browser/extensions/api/messaging/message_service.h b/chrome/browser/extensions/api/messaging/message_service.h
index df760f3..69c23ef 100644
--- a/chrome/browser/extensions/api/messaging/message_service.h
+++ b/chrome/browser/extensions/api/messaging/message_service.h
@@ -22,7 +22,6 @@ class Profile;
 
 namespace base {
 class DictionaryValue;
-class ListValue;
 }
 
 namespace content {
@@ -83,7 +82,7 @@ class MessageService : public ProfileKeyedAPI,
                                       const std::string& error_message) {}
 
     // Dispatch a message to this end of the communication.
-    virtual void DispatchOnMessage(scoped_ptr<base::ListValue> message,
+    virtual void DispatchOnMessage(const std::string& message,
                                    int target_port_id) = 0;
 
     // MessagPorts that target extensions will need to adjust their keepalive
@@ -145,12 +144,12 @@ class MessageService : public ProfileKeyedAPI,
                             const std::string& error_message) OVERRIDE;
 
   // Sends a message to the given port.
-  void PostMessage(int port_id, scoped_ptr<base::ListValue> message);
+  void PostMessage(int port_id, const std::string& message);
 
   // NativeMessageProcessHost::Client
   virtual void PostMessageFromNativeProcess(
       int port_id,
-      scoped_ptr<base::ListValue> message) OVERRIDE;
+      const std::string& message) OVERRIDE;
 
  private:
   friend class MockMessageService;
@@ -206,10 +205,10 @@ class MessageService : public ProfileKeyedAPI,
       CloseChannel(port_id, error_message);
   }
   void PendingPostMessage(int port_id,
-                          scoped_ptr<base::ListValue> message,
+                          const std::string& message,
                           extensions::ExtensionHost* host) {
     if (host)
-      PostMessage(port_id, message.Pass());
+      PostMessage(port_id, message);
   }
 
   // ProfileKeyedAPI implementation.
diff --git a/chrome/browser/extensions/api/messaging/native_message_port.cc b/chrome/browser/extensions/api/messaging/native_message_port.cc
index c340e33..cc0a4cf 100644
--- a/chrome/browser/extensions/api/messaging/native_message_port.cc
+++ b/chrome/browser/extensions/api/messaging/native_message_port.cc
@@ -4,8 +4,6 @@
 
 #include "chrome/browser/extensions/api/messaging/native_message_port.h"
 
-#include "base/bind.h"
-#include "base/json/json_writer.h"
 #include "chrome/browser/extensions/api/messaging/native_message_process_host.h"
 #include "content/public/browser/browser_thread.h"
 
@@ -20,20 +18,12 @@ NativeMessagePort::~NativeMessagePort() {
       content::BrowserThread::IO, FROM_HERE, native_process_);
 }
 
-void NativeMessagePort::DispatchOnMessage(scoped_ptr<base::ListValue> message,
+void NativeMessagePort::DispatchOnMessage(const std::string& message,
                                           int target_port_id) {
-  std::string message_as_json;
-  if (!message->empty()) {
-    DCHECK_EQ(1u, message->GetSize());
-    base::Value* value = NULL;
-    message->Get(0, &value);
-    base::JSONWriter::Write(value, &message_as_json);
-  }
   content::BrowserThread::PostTask(
       content::BrowserThread::IO, FROM_HERE,
       base::Bind(&NativeMessageProcessHost::Send,
-                 base::Unretained(native_process_),
-                 message_as_json));
+                 base::Unretained(native_process_), message));
 }
 
 }  // namespace extensions
diff --git a/chrome/browser/extensions/api/messaging/native_message_port.h b/chrome/browser/extensions/api/messaging/native_message_port.h
index 4c88445..6afce8a 100644
--- a/chrome/browser/extensions/api/messaging/native_message_port.h
+++ b/chrome/browser/extensions/api/messaging/native_message_port.h
@@ -16,7 +16,7 @@ class NativeMessagePort : public MessageService::MessagePort {
   // Takes ownership of |native_process|.
   explicit NativeMessagePort(NativeMessageProcessHost* native_process);
   virtual ~NativeMessagePort();
-  virtual void DispatchOnMessage(scoped_ptr<base::ListValue> message,
+  virtual void DispatchOnMessage(const std::string& message,
                                  int target_port_id) OVERRIDE;
 
  private:
diff --git a/chrome/browser/extensions/api/messaging/native_message_process_host.cc b/chrome/browser/extensions/api/messaging/native_message_process_host.cc
index 9f8c50b..9187a08 100644
--- a/chrome/browser/extensions/api/messaging/native_message_process_host.cc
+++ b/chrome/browser/extensions/api/messaging/native_message_process_host.cc
@@ -5,9 +5,7 @@
 #include "chrome/browser/extensions/api/messaging/native_message_process_host.h"
 
 #include "base/bind.h"
-#include "base/bind_helpers.h"
 #include "base/files/file_path.h"
-#include "base/json/json_reader.h"
 #include "base/logging.h"
 #include "base/platform_file.h"
 #include "base/process_util.h"
@@ -44,8 +42,6 @@ const char kForbiddenError[] =
     "Access to the specified native messaging host is forbidden.";
 const char kHostInputOuputError[] =
     "Error when communicating with the native messaging host.";
-const char kInvalidJsonError[] =
-    "Message must be valid JSON";
 
 }  // namespace
 
@@ -272,35 +268,10 @@ void NativeMessageProcessHost::ProcessIncomingData(
     if (incoming_data_.size() < message_size + kMessageHeaderSize)
       return;
 
-    scoped_ptr<base::ListValue> message(new base::ListValue());
-    {
-      std::string message_as_json =
-          incoming_data_.substr(kMessageHeaderSize, message_size);
-      int error_code;
-      std::string error_message;
-      scoped_ptr<base::Value> message_as_value(
-          base::JSONReader::ReadAndReturnError(message_as_json,
-                                               0,  // no flags
-                                               &error_code,
-                                               &error_message));
-      if (!message_as_value) {
-        base::JSONReader::JsonParseError parse_error =
-            static_cast<base::JSONReader::JsonParseError>(error_code);
-        LOG(ERROR) << "Native Messaging host sent message with invalid JSON \""
-                   << message_as_json << "\": " << error_message << " ("
-                   << base::JSONReader::ErrorCodeToString(parse_error) << "), "
-                   << "message size " << message_size << ", "
-                   << "incoming data size " << incoming_data_.size() << ".";
-        Close(kInvalidJsonError);
-        return;
-      }
-      message->Append(message_as_value.release());
-    }
-
     content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
         base::Bind(&Client::PostMessageFromNativeProcess, weak_client_ui_,
             destination_port_,
-            base::Passed(&message)));
+            incoming_data_.substr(kMessageHeaderSize, message_size)));
 
     incoming_data_.erase(0, kMessageHeaderSize + message_size);
   }
diff --git a/chrome/browser/extensions/api/messaging/native_message_process_host.h b/chrome/browser/extensions/api/messaging/native_message_process_host.h
index ef339b2..987055f 100644
--- a/chrome/browser/extensions/api/messaging/native_message_process_host.h
+++ b/chrome/browser/extensions/api/messaging/native_message_process_host.h
@@ -15,15 +15,13 @@
 #include "chrome/browser/extensions/api/messaging/native_process_launcher.h"
 #include "content/public/browser/browser_thread.h"
 
-namespace base {
-class ListValue;
-}
-
 namespace net {
+
 class DrainableIOBuffer;
 class FileStream;
 class IOBuffer;
 class IOBufferWithSize;
+
 }  // namespace net
 
 namespace extensions {
@@ -45,9 +43,8 @@ class NativeMessageProcessHost
    public:
     virtual ~Client() {}
     // Called on the UI thread.
-    virtual void PostMessageFromNativeProcess(
-        int port_id,
-        scoped_ptr<base::ListValue> message) = 0;
+    virtual void PostMessageFromNativeProcess(int port_id,
+                                              const std::string& message) = 0;
     virtual void CloseChannel(int port_id,
                               const std::string& error_message) = 0;
   };
diff --git a/chrome/browser/extensions/api/messaging/native_message_process_host_unittest.cc b/chrome/browser/extensions/api/messaging/native_message_process_host_unittest.cc
index ad4ad6b..080be62 100644
--- a/chrome/browser/extensions/api/messaging/native_message_process_host_unittest.cc
+++ b/chrome/browser/extensions/api/messaging/native_message_process_host_unittest.cc
@@ -109,15 +109,19 @@ class NativeMessagingTest : public ::testing::Test,
 
   virtual void PostMessageFromNativeProcess(
       int port_id,
-      scoped_ptr<base::ListValue> message_as_list) OVERRIDE  {
-    // |message_as_list| should contain a single DictionaryValue. Extract it
-    // into |last_message_|.
-    ASSERT_EQ(1u, message_as_list->GetSize());
-    base::Value* last_message_value = NULL;
-    message_as_list->Remove(0, &last_message_value);
-    ASSERT_EQ(base::Value::TYPE_DICTIONARY, last_message_value->GetType());
-    last_message_.reset(
-        static_cast<base::DictionaryValue*>(last_message_value));
+      const std::string& message) OVERRIDE  {
+    last_message_ = message;
+
+    // Parse the message.
+    base::Value* parsed = base::JSONReader::Read(message);
+    base::DictionaryValue* dict_value;
+    if (parsed && parsed->GetAsDictionary(&dict_value)) {
+      last_message_parsed_.reset(dict_value);
+    } else {
+      LOG(ERROR) << "Failed to parse " << message;
+      last_message_parsed_.reset();
+      delete parsed;
+    }
 
     if (read_message_run_loop_)
       read_message_run_loop_->Quit();
@@ -153,7 +157,8 @@ class NativeMessagingTest : public ::testing::Test,
   scoped_ptr<base::RunLoop> read_message_run_loop_;
   scoped_ptr<content::TestBrowserThread> ui_thread_;
   scoped_ptr<content::TestBrowserThread> io_thread_;
-  scoped_ptr<DictionaryValue> last_message_;
+  std::string last_message_;
+  scoped_ptr<base::DictionaryValue> last_message_parsed_;
 };
 
 // Read a single message from a local file.
@@ -170,26 +175,19 @@ TEST_F(NativeMessagingTest, SingleSendMessageRead) {
   read_message_run_loop_.reset(new base::RunLoop());
   read_message_run_loop_->RunUntilIdle();
 
-  if (!last_message_) {
+  if (last_message_.empty()) {
     read_message_run_loop_.reset(new base::RunLoop());
     native_message_process_host_->ReadNowForTesting();
     read_message_run_loop_->Run();
   }
-  ASSERT_TRUE(last_message_);
-
-  scoped_ptr<base::Value> kTestMessageAsValue(
-      base::JSONReader::Read(kTestMessage));
-  ASSERT_TRUE(kTestMessageAsValue);
-  EXPECT_TRUE(base::Value::Equals(kTestMessageAsValue.get(),
-                                  last_message_.get()))
-      << "Expected " << *kTestMessageAsValue << " got " << *last_message_;
+  EXPECT_EQ(kTestMessage, last_message_);
 }
 
 // Tests sending a single message. The message should get written to
 // |temp_file| and should match the contents of single_message_request.msg.
 TEST_F(NativeMessagingTest, SingleSendMessageWrite) {
   base::FilePath temp_output_file = temp_dir_.path().AppendASCII("output");
-  base::FilePath temp_input_file = CreateTempFileWithMessage("{}");
+  base::FilePath temp_input_file = CreateTempFileWithMessage(std::string());
 
   scoped_ptr<NativeProcessLauncher> launcher(
       new FakeLauncher(temp_input_file, temp_output_file));
@@ -235,29 +233,30 @@ TEST_F(NativeMessagingTest, EchoConnect) {
   native_message_process_host_->Send("{\"text\": \"Hello.\"}");
   read_message_run_loop_.reset(new base::RunLoop());
   read_message_run_loop_->Run();
-  ASSERT_TRUE(last_message_);
+  ASSERT_FALSE(last_message_.empty());
+  ASSERT_TRUE(last_message_parsed_);
 
   std::string expected_url = std::string("chrome-extension://") +
       kTestNativeMessagingExtensionId + "/";
   int id;
-  EXPECT_TRUE(last_message_->GetInteger("id", &id));
+  EXPECT_TRUE(last_message_parsed_->GetInteger("id", &id));
   EXPECT_EQ(1, id);
   std::string text;
-  EXPECT_TRUE(last_message_->GetString("echo.text", &text));
+  EXPECT_TRUE(last_message_parsed_->GetString("echo.text", &text));
   EXPECT_EQ("Hello.", text);
   std::string url;
-  EXPECT_TRUE(last_message_->GetString("caller_url", &url));
+  EXPECT_TRUE(last_message_parsed_->GetString("caller_url", &url));
   EXPECT_EQ(expected_url, url);
 
 
   native_message_process_host_->Send("{\"foo\": \"bar\"}");
   read_message_run_loop_.reset(new base::RunLoop());
   read_message_run_loop_->Run();
-  EXPECT_TRUE(last_message_->GetInteger("id", &id));
+  EXPECT_TRUE(last_message_parsed_->GetInteger("id", &id));
   EXPECT_EQ(2, id);
-  EXPECT_TRUE(last_message_->GetString("echo.foo", &text));
+  EXPECT_TRUE(last_message_parsed_->GetString("echo.foo", &text));
   EXPECT_EQ("bar", text);
-  EXPECT_TRUE(last_message_->GetString("caller_url", &url));
+  EXPECT_TRUE(last_message_parsed_->GetString("caller_url", &url));
   EXPECT_EQ(expected_url, url);
 }
 
diff --git a/chrome/browser/extensions/message_handler.cc b/chrome/browser/extensions/message_handler.cc
index f0576e5..79b94c9 100644
--- a/chrome/browser/extensions/message_handler.cc
+++ b/chrome/browser/extensions/message_handler.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/extensions/message_handler.h"
 
-#include "base/values.h"
 #include "chrome/browser/extensions/api/messaging/message_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/profiles/profile.h"
@@ -44,12 +43,12 @@ void MessageHandler::RenderViewHostInitialized() {
 }
 
 void MessageHandler::OnPostMessage(int port_id,
-                                   const base::ListValue& message) {
+                                            const std::string& message) {
   Profile* profile = Profile::FromBrowserContext(
       render_view_host()->GetProcess()->GetBrowserContext());
   MessageService* message_service = MessageService::Get(profile);
   if (message_service) {
-    message_service->PostMessage(port_id, make_scoped_ptr(message.DeepCopy()));
+    message_service->PostMessage(port_id, message);
   }
 }
 
diff --git a/chrome/browser/extensions/message_handler.h b/chrome/browser/extensions/message_handler.h
index 7142682..140105d 100644
--- a/chrome/browser/extensions/message_handler.h
+++ b/chrome/browser/extensions/message_handler.h
@@ -9,10 +9,6 @@
 
 #include "content/public/browser/render_view_host_observer.h"
 
-namespace base {
-class ListValue;
-}
-
 namespace extensions {
 
 // Filters and dispatches extension-related IPC messages that arrive from
@@ -37,7 +33,7 @@ class MessageHandler : public content::RenderViewHostObserver {
 
  private:
   // Message handlers.
-  void OnPostMessage(int port_id, const base::ListValue& message);
+  void OnPostMessage(int port_id, const std::string& message);
 
   DISALLOW_COPY_AND_ASSIGN(MessageHandler);
 };
diff --git a/chrome/common/extensions/extension_messages.h b/chrome/common/extensions/extension_messages.h
index 8a03307..b4eaee2 100644
--- a/chrome/common/extensions/extension_messages.h
+++ b/chrome/common/extensions/extension_messages.h
@@ -419,7 +419,7 @@ IPC_MESSAGE_ROUTED4(ExtensionMsg_DispatchOnConnect,
 // Deliver a message sent with ExtensionHostMsg_PostMessage.
 IPC_MESSAGE_ROUTED2(ExtensionMsg_DeliverMessage,
                     int /* target_port_id */,
-                    ListValue /* message arguments, a 0-or-1 length list */)
+                    std::string /* message */)
 
 // Dispatch the Port.onDisconnect event for message channels.
 IPC_MESSAGE_ROUTED2(ExtensionMsg_DispatchOnDisconnect,
@@ -529,7 +529,7 @@ IPC_SYNC_MESSAGE_CONTROL4_1(ExtensionHostMsg_OpenChannelToTab,
 // by ViewHostMsg_OpenChannelTo*.
 IPC_MESSAGE_ROUTED2(ExtensionHostMsg_PostMessage,
                     int /* port_id */,
-                    ListValue /* message arguments, a 0-or-1 length list */)
+                    std::string /* message */)
 
 // Send a message to an extension process.  The handle is the value returned
 // by ViewHostMsg_OpenChannelTo*.
diff --git a/chrome/renderer/extensions/dispatcher.cc b/chrome/renderer/extensions/dispatcher.cc
index 7d0d01f..ea89a3f 100644
--- a/chrome/renderer/extensions/dispatcher.cc
+++ b/chrome/renderer/extensions/dispatcher.cc
@@ -595,7 +595,7 @@ void Dispatcher::OnDispatchOnConnect(
 }
 
 void Dispatcher::OnDeliverMessage(int target_port_id,
-                                  const base::ListValue& message) {
+                                  const std::string& message) {
   MiscellaneousBindings::DeliverMessage(
       v8_context_set_.GetAll(),
       target_port_id,
diff --git a/chrome/renderer/extensions/dispatcher.h b/chrome/renderer/extensions/dispatcher.h
index 44e80bf..ec002ad 100644
--- a/chrome/renderer/extensions/dispatcher.h
+++ b/chrome/renderer/extensions/dispatcher.h
@@ -151,7 +151,7 @@ class Dispatcher : public content::RenderProcessObserver {
                            const std::string& channel_name,
                            const base::DictionaryValue& source_tab,
                            const ExtensionMsg_ExternalConnectionInfo& info);
-  void OnDeliverMessage(int target_port_id, const base::ListValue& message);
+  void OnDeliverMessage(int target_port_id, const std::string& message);
   void OnDispatchOnDisconnect(int port_id, const std::string& error_message);
   void OnSetFunctionNames(const std::vector<std::string>& names);
   void OnLoaded(
diff --git a/chrome/renderer/extensions/extension_helper.cc b/chrome/renderer/extensions/extension_helper.cc
index a5e7ef4..c61221b 100644
--- a/chrome/renderer/extensions/extension_helper.cc
+++ b/chrome/renderer/extensions/extension_helper.cc
@@ -274,9 +274,8 @@ void ExtensionHelper::OnExtensionDispatchOnConnect(
       render_view());
 }
 
-void ExtensionHelper::OnExtensionDeliverMessage(
-    int target_id,
-    const base::ListValue& message) {
+void ExtensionHelper::OnExtensionDeliverMessage(int target_id,
+                                                const std::string& message) {
   MiscellaneousBindings::DeliverMessage(dispatcher_->v8_context_set().GetAll(),
                                         target_id,
                                         message,
diff --git a/chrome/renderer/extensions/extension_helper.h b/chrome/renderer/extensions/extension_helper.h
index 6e8fc97..fcb82b1 100644
--- a/chrome/renderer/extensions/extension_helper.h
+++ b/chrome/renderer/extensions/extension_helper.h
@@ -80,7 +80,7 @@ class ExtensionHelper
       const base::DictionaryValue& source_tab,
       const ExtensionMsg_ExternalConnectionInfo& info);
   void OnExtensionDeliverMessage(int target_port_id,
-                                 const base::ListValue& message);
+                                 const std::string& message);
   void OnExtensionDispatchOnDisconnect(int port_id,
                                        const std::string& error_message);
   void OnExecuteCode(const ExtensionMsg_ExecuteCode_Params& params);
diff --git a/chrome/renderer/extensions/miscellaneous_bindings.cc b/chrome/renderer/extensions/miscellaneous_bindings.cc
index d7e591d..d40d517 100644
--- a/chrome/renderer/extensions/miscellaneous_bindings.cc
+++ b/chrome/renderer/extensions/miscellaneous_bindings.cc
@@ -95,65 +95,43 @@ class ExtensionImpl : public extensions::ChromeV8Extension {
     if (!renderview)
       return v8::Undefined();
 
-    // Arguments are (int32 port_id, object message).
-    CHECK_EQ(2, args.Length());
-    CHECK(args[0]->IsInt32());
-
-    int port_id = args[0]->Int32Value();
-    if (!HasPortData(port_id)) {
-      return v8::ThrowException(v8::Exception::Error(
-        v8::String::New(kPortClosedError)));
+    if (args.Length() >= 2 && args[0]->IsInt32() && args[1]->IsString()) {
+      int port_id = args[0]->Int32Value();
+      if (!HasPortData(port_id)) {
+        return v8::ThrowException(v8::Exception::Error(
+          v8::String::New(kPortClosedError)));
+      }
+      std::string message = *v8::String::Utf8Value(args[1]->ToString());
+      renderview->Send(new ExtensionHostMsg_PostMessage(
+          renderview->GetRoutingID(), port_id, message));
     }
-
-    // The message can be any base::Value but IPC can't serialize that, so we
-    // give it a singleton base::ListValue instead, or an empty list if the
-    // argument was undefined (v8 value converter will return NULL for this).
-    scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
-    scoped_ptr<base::Value> message(
-        converter->FromV8Value(args[1], v8_context()));
-    ListValue message_as_list;
-    if (message)
-      message_as_list.Append(message.release());
-
-    renderview->Send(new ExtensionHostMsg_PostMessage(
-        renderview->GetRoutingID(), port_id, message_as_list));
-
     return v8::Undefined();
   }
 
   // Forcefully disconnects a port.
   v8::Handle<v8::Value> CloseChannel(const v8::Arguments& args) {
-    // Arguments are (int32 port_id, boolean notify_browser).
-    CHECK_EQ(2, args.Length());
-    CHECK(args[0]->IsInt32());
-    CHECK(args[1]->IsBoolean());
-
-    int port_id = args[0]->Int32Value();
-    if (!HasPortData(port_id))
-      return v8::Undefined();
-
-    // Send via the RenderThread because the RenderView might be closing.
-    bool notify_browser = args[1]->BooleanValue();
-    if (notify_browser) {
-      content::RenderThread::Get()->Send(
-          new ExtensionHostMsg_CloseChannel(port_id, std::string()));
+    if (args.Length() >= 2 && args[0]->IsInt32() && args[1]->IsBoolean()) {
+      int port_id = args[0]->Int32Value();
+      if (!HasPortData(port_id)) {
+        return v8::Undefined();
+      }
+      // Send via the RenderThread because the RenderView might be closing.
+      bool notify_browser = args[1]->BooleanValue();
+      if (notify_browser)
+        content::RenderThread::Get()->Send(
+            new ExtensionHostMsg_CloseChannel(port_id, std::string()));
+      ClearPortData(port_id);
     }
-
-    ClearPortData(port_id);
-
     return v8::Undefined();
   }
 
   // A new port has been created for a context.  This occurs both when script
   // opens a connection, and when a connection is opened to this script.
   v8::Handle<v8::Value> PortAddRef(const v8::Arguments& args) {
-    // Arguments are (int32 port_id).
-    CHECK_EQ(1, args.Length());
-    CHECK(args[0]->IsInt32());
-
-    int port_id = args[0]->Int32Value();
-    ++GetPortData(port_id).ref_count;
-
+    if (args.Length() >= 1 && args[0]->IsInt32()) {
+      int port_id = args[0]->Int32Value();
+      ++GetPortData(port_id).ref_count;
+    }
     return v8::Undefined();
   }
 
@@ -161,18 +139,15 @@ class ExtensionImpl : public extensions::ChromeV8Extension {
   // frames with a reference to a given port, we will disconnect it and notify
   // the other end of the channel.
   v8::Handle<v8::Value> PortRelease(const v8::Arguments& args) {
-    // Arguments are (int32 port_id).
-    CHECK_EQ(1, args.Length());
-    CHECK(args[0]->IsInt32());
-
-    int port_id = args[0]->Int32Value();
-    if (HasPortData(port_id) && --GetPortData(port_id).ref_count == 0) {
-      // Send via the RenderThread because the RenderView might be closing.
-      content::RenderThread::Get()->Send(
-          new ExtensionHostMsg_CloseChannel(port_id, std::string()));
-      ClearPortData(port_id);
+    if (args.Length() >= 1 && args[0]->IsInt32()) {
+      int port_id = args[0]->Int32Value();
+      if (HasPortData(port_id) && --GetPortData(port_id).ref_count == 0) {
+        // Send via the RenderThread because the RenderView might be closing.
+        content::RenderThread::Get()->Send(
+            new ExtensionHostMsg_CloseChannel(port_id, std::string()));
+        ClearPortData(port_id);
+      }
     }
-
     return v8::Undefined();
   }
 
@@ -296,7 +271,7 @@ void MiscellaneousBindings::DispatchOnConnect(
 void MiscellaneousBindings::DeliverMessage(
     const ChromeV8ContextSet::ContextSet& contexts,
     int target_port_id,
-    const base::ListValue& message,
+    const std::string& message,
     content::RenderView* restrict_to_render_view) {
   v8::HandleScope handle_scope;
 
@@ -307,9 +282,6 @@ void MiscellaneousBindings::DeliverMessage(
       continue;
     }
 
-    v8::Handle<v8::Context> context = (*it)->v8_context();
-    v8::Context::Scope context_scope(context);
-
     // Check to see whether the context has this port before bothering to create
     // the message.
     v8::Handle<v8::Value> port_id_handle = v8::Integer::New(target_port_id);
@@ -330,19 +302,7 @@ void MiscellaneousBindings::DeliverMessage(
       continue;
 
     std::vector<v8::Handle<v8::Value> > arguments;
-
-    // Convert the message to a v8 object; either a value or undefined.
-    // See PostMessage for more details.
-    if (message.empty()) {
-      arguments.push_back(v8::Undefined());
-    } else {
-      CHECK_EQ(1u, message.GetSize());
-      const base::Value* message_value = NULL;
-      message.Get(0, &message_value);
-      scoped_ptr<V8ValueConverter> converter(V8ValueConverter::create());
-      arguments.push_back(converter->ToV8Value(message_value, context));
-    }
-
+    arguments.push_back(v8::String::New(message.c_str(), message.size()));
     arguments.push_back(port_id_handle);
     CHECK((*it)->CallChromeHiddenMethod("Port.dispatchOnMessage",
                                         arguments.size(),
diff --git a/chrome/renderer/extensions/miscellaneous_bindings.h b/chrome/renderer/extensions/miscellaneous_bindings.h
index 0a769d2..33bb15e 100644
--- a/chrome/renderer/extensions/miscellaneous_bindings.h
+++ b/chrome/renderer/extensions/miscellaneous_bindings.h
@@ -11,7 +11,6 @@
 
 namespace base {
 class DictionaryValue;
-class ListValue;
 }
 
 namespace content {
@@ -56,7 +55,7 @@ class MiscellaneousBindings {
   static void DeliverMessage(
       const ChromeV8ContextSet::ContextSet& context_set,
       int target_port_id,
-      const base::ListValue& message,
+      const std::string& message,
       content::RenderView* restrict_to_render_view);
 
   // Dispatches the Port.onDisconnect event in response to the channel being
diff --git a/chrome/renderer/resources/extensions/miscellaneous_bindings.js b/chrome/renderer/resources/extensions/miscellaneous_bindings.js
index 7dbfe29..9a4937d 100644
--- a/chrome/renderer/resources/extensions/miscellaneous_bindings.js
+++ b/chrome/renderer/resources/extensions/miscellaneous_bindings.js
@@ -8,6 +8,7 @@
 // content scripts only.
 
   require('json_schema');
+  var json = require('json');
   var lastError = require('lastError');
   var miscNatives = requireNative('miscellaneous_bindings');
   var chrome = requireNative('chrome').GetChrome();
@@ -54,7 +55,10 @@
   // Sends a message asynchronously to the context on the other end of this
   // port.
   PortImpl.prototype.postMessage = function(msg) {
-    PostMessage(this.portId_, msg);
+    // json.stringify doesn't support a root object which is undefined.
+    if (msg === undefined)
+      msg = null;
+    PostMessage(this.portId_, json.stringify(msg));
   };
 
   // Disconnects the port from the other end.
@@ -262,8 +266,12 @@
   // Called by native code when a message has been sent to the given port.
   chromeHidden.Port.dispatchOnMessage = function(msg, portId) {
     var port = ports[portId];
-    if (port)
+    if (port) {
+      if (msg) {
+        msg = json.parse(msg);
+      }
       port.onMessage.dispatch(msg, port);
+    }
   };
 
   // Shared implementation used by tabs.sendMessage and runtime.sendMessage.
diff --git a/chrome/test/data/devtools/extensions/devtools_messaging/devtools.js b/chrome/test/data/devtools/extensions/devtools_messaging/devtools.js
index 915273b..56c2f14 100644
--- a/chrome/test/data/devtools/extensions/devtools_messaging/devtools.js
+++ b/chrome/test/data/devtools/extensions/devtools_messaging/devtools.js
@@ -30,7 +30,7 @@ function step1() {
 }
 
 function step2() {
-  var object = [{"string": "foo"}, {"number": 42}];
+  var object = { "string": "foo", "number": 42 };
   chrome.extension.sendRequest(object, function(response) {
     assertEquals('onRequest callback: ' + JSON.stringify(object), response);
     step3();