Message receiver on browser side that holds/starts the gamepad data provider

Messages are already committed, and the patch that sends the messages from the
renderer side is here: http://codereview.chromium.org/8689011/ (at the top of
content/renderer/gamepad_util.cc)

re: AllowScopedIO in Stop(), I copied startup/shutdown from somewhere that I
didn't realize had that problem. Will follow up to figure out how to shut down
cleanly.

BUG=79050


Review URL: http://codereview.chromium.org/8689012

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@111624 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/renderer_host/gamepad_browser_message_filter.cc

+// Copyright (c) 2011 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 "content/browser/renderer_host/gamepad_browser_message_filter.h"
+
+#include "content/common/gamepad_messages.h"
+
+GamepadBrowserMessageFilter::GamepadBrowserMessageFilter() {
+}
+
+GamepadBrowserMessageFilter::~GamepadBrowserMessageFilter() {
+}
+
+bool GamepadBrowserMessageFilter::OnMessageReceived(
+    const IPC::Message& message,
+    bool* message_was_ok) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(GamepadBrowserMessageFilter,
+                           message,
+                           *message_was_ok)
+    IPC_MESSAGE_HANDLER(GamepadHostMsg_StartPolling, OnGamepadStartPolling)
+    IPC_MESSAGE_HANDLER(GamepadHostMsg_StopPolling, OnGamepadStopPolling)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP_EX()
+  return handled;
+}
+
+void GamepadBrowserMessageFilter::OnGamepadStartPolling(
+    base::SharedMemoryHandle* renderer_handle) {
+  if (!provider_) {
+    provider_ = new gamepad::Provider(NULL);
+    provider_->Start();
+  }
+  *renderer_handle = provider_->GetRendererSharedMemoryHandle(peer_handle());
+}
+
+void GamepadBrowserMessageFilter::OnGamepadStopPolling() {
+  // TODO(scottmg) Remove this message entirely?
+  // Stop is currently handled by the refcount on provider_.
+}

content/browser/renderer_host/gamepad_browser_message_filter.h

+// Copyright (c) 2011 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.
+
+#ifndef CONTENT_BROWSER_RENDERER_HOST_GAMEPAD_BROWSER_MESSAGE_FILTER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_GAMEPAD_BROWSER_MESSAGE_FILTER_H_
+#pragma once
+
+#include "content/browser/browser_message_filter.h"
+#include "content/browser/gamepad/gamepad_provider.h"
+
+class GamepadBrowserMessageFilter : public BrowserMessageFilter {
+ public:
+  // BrowserMessageFilter implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok);
+  GamepadBrowserMessageFilter();
+
+ private:
+  virtual ~GamepadBrowserMessageFilter();
+
+  void OnGamepadStartPolling(base::SharedMemoryHandle* renderer_handle);
+  void OnGamepadStopPolling();
+
+  scoped_refptr<gamepad::Provider> provider_;
+
+  DISALLOW_COPY_AND_ASSIGN(GamepadBrowserMessageFilter);
+};
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_GAMEPAD_BROWSER_MESSAGE_FILTER_H_

content/browser/renderer_host/render_process_host_impl.cc

@@ -52,6 +52,7 @@
 #include "content/browser/renderer_host/clipboard_message_filter.h"
 #include "content/browser/renderer_host/database_message_filter.h"
 #include "content/browser/renderer_host/file_utilities_message_filter.h"
+#include "content/browser/renderer_host/gamepad_browser_message_filter.h"
 #include "content/browser/renderer_host/gpu_message_filter.h"
 #include "content/browser/renderer_host/media/audio_input_renderer_host.h"
 #include "content/browser/renderer_host/media/audio_renderer_host.h"
@@ -532,6 +533,7 @@ void RenderProcessHostImpl::CreateMessageFilters() {
   channel_->AddFilter(new QuotaDispatcherHost(
       GetID(), GetBrowserContext()->GetQuotaManager(),
       content::GetContentClient()->browser()->CreateQuotaPermissionContext()));
+  channel_->AddFilter(new GamepadBrowserMessageFilter);
 }
 
 int RenderProcessHostImpl::GetNextRoutingID() {

content/content_browser.gypi

@@ -369,6 +369,8 @@
     'browser/renderer_host/database_message_filter.h',
     'browser/renderer_host/file_utilities_message_filter.cc',
     'browser/renderer_host/file_utilities_message_filter.h',
+    'browser/renderer_host/gamepad_browser_message_filter.cc',
+    'browser/renderer_host/gamepad_browser_message_filter.h',
     'browser/renderer_host/global_request_id.h',
     'browser/renderer_host/gpu_message_filter.cc',
     'browser/renderer_host/gpu_message_filter.h',