Refactor: Simplify WaitableEventWatcher.

This change uses a callback instead of a delegate for specifying what
should be called when a WaitableEvent occurs.

This simplifies the class and gets rid of a workaround internal to the
class to prevent name collision on "Delegate" inner classes.

Tested (on linux and windows):
  ninja -C out/Debug chrome
  out/Debug/base_unittests --gtest_filter=*WaitableEventWatcherTest*

BUG=


Review URL: https://chromiumcodereview.appspot.com/11953112

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@179987 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 16 insertions, 11 deletions

diff --git a/content/browser/plugin_data_remover_impl_browsertest.cc b/content/browser/plugin_data_remover_impl_browsertest.cc
index 101987d..98b06d7 100644
--- a/content/browser/plugin_data_remover_impl_browsertest.cc
+++ b/content/browser/plugin_data_remover_impl_browsertest.cc
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 #include "base/base_paths.h"
+#include "base/callback.h"
 #include "base/command_line.h"
 #include "base/path_service.h"
 #include "base/synchronization/waitable_event_watcher.h"
@@ -19,12 +20,11 @@ namespace {
 const char* kNPAPITestPluginMimeType = "application/vnd.npapi-test";
 }
 
-class PluginDataRemoverTest : public ContentBrowserTest,
-                              public base::WaitableEventWatcher::Delegate {
+class PluginDataRemoverTest : public ContentBrowserTest {
  public:
   PluginDataRemoverTest() {}
 
-  virtual void OnWaitableEventSignaled(base::WaitableEvent* waitable_event) {
+  void OnWaitableEventSignaled(base::WaitableEvent* waitable_event) {
     MessageLoop::current()->Quit();
   }
 
@@ -51,7 +51,9 @@ IN_PROC_BROWSER_TEST_F(PluginDataRemoverTest, RemoveData) {
   base::WaitableEventWatcher watcher;
   base::WaitableEvent* event =
       plugin_data_remover.StartRemoving(base::Time());
-  watcher.StartWatching(event, this);
+  watcher.StartWatching(
+      event,
+      base::Bind(&PluginDataRemoverTest::OnWaitableEventSignaled, this));
   RunMessageLoop();
 }
 
diff --git a/content/browser/plugin_service_impl.cc b/content/browser/plugin_service_impl.cc
index 9b90fe0..e083774 100644
--- a/content/browser/plugin_service_impl.cc
+++ b/content/browser/plugin_service_impl.cc
@@ -186,7 +186,10 @@ void PluginServiceImpl::StartWatchingPlugins() {
                        KEY_NOTIFY) == ERROR_SUCCESS) {
     if (hkcu_key_.StartWatching() == ERROR_SUCCESS) {
       hkcu_event_.reset(new base::WaitableEvent(hkcu_key_.watch_event()));
-      hkcu_watcher_.StartWatching(hkcu_event_.get(), this);
+      base::WaitableEventWatcher::EventCallback callback =
+            base::Bind(&PluginServiceImpl::OnWaitableEventSignaled,
+                       base::Unretained(this));
+      hkcu_watcher_.StartWatching(hkcu_event_.get(), callback);
     }
   }
   if (hklm_key_.Create(HKEY_LOCAL_MACHINE,
@@ -194,7 +197,10 @@ void PluginServiceImpl::StartWatchingPlugins() {
                        KEY_NOTIFY) == ERROR_SUCCESS) {
     if (hklm_key_.StartWatching() == ERROR_SUCCESS) {
       hklm_event_.reset(new base::WaitableEvent(hklm_key_.watch_event()));
-      hklm_watcher_.StartWatching(hklm_event_.get(), this);
+      base::WaitableEventWatcher::EventCallback callback =
+            base::Bind(&PluginServiceImpl::OnWaitableEventSignaled,
+                       base::Unretained(this));
+      hklm_watcher_.StartWatching(hklm_event_.get(), callback);
     }
   }
 #endif
diff --git a/content/browser/plugin_service_impl.h b/content/browser/plugin_service_impl.h
index 8808c4b..81ef427 100644
--- a/content/browser/plugin_service_impl.h
+++ b/content/browser/plugin_service_impl.h
@@ -64,8 +64,7 @@ struct PluginServiceFilterParams {
 };
 
 class CONTENT_EXPORT PluginServiceImpl
-    : NON_EXPORTED_BASE(public PluginService),
-      public base::WaitableEventWatcher::Delegate {
+    : NON_EXPORTED_BASE(public PluginService) {
  public:
   // Returns the PluginServiceImpl singleton.
   static PluginServiceImpl* GetInstance();
@@ -157,9 +156,7 @@ class CONTENT_EXPORT PluginServiceImpl
   PluginServiceImpl();
   virtual ~PluginServiceImpl();
 
-  // base::WaitableEventWatcher::Delegate implementation.
-  virtual void OnWaitableEventSignaled(
-      base::WaitableEvent* waitable_event) OVERRIDE;
+  void OnWaitableEventSignaled(base::WaitableEvent* waitable_event);
 
   // Returns the plugin process host corresponding to the plugin process that
   // has been started by this service. Returns NULL if no process has been