Revert 159158 - Make using WebContentsUserData simpler.

BUG=107201
TEST=no visible change

Reverted due to bug 152950

Review URL: https://chromiumcodereview.appspot.com/10993064

TBR=avi@chromium.org
Review URL: https://codereview.chromium.org/10990113

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@159277 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 13 insertions, 21 deletions

diff --git a/chrome/browser/common/web_contents_user_data.h b/chrome/browser/common/web_contents_user_data.h
index 364997e..2cffb58 100644
--- a/chrome/browser/common/web_contents_user_data.h
+++ b/chrome/browser/common/web_contents_user_data.h
@@ -18,11 +18,12 @@
 //   // ... more public stuff here ...
 //  private:
 //   explicit FooTabHelper(content::WebContents* contents);
+//   static int kUserDataKey;
 //   friend class WebContentsUserData<FooTabHelper>;
 //   // ... more private stuff here ...
 // }
 // --- in foo_tab_helper.cc ---
-// DEFINE_WEB_CONTENTS_USER_DATA_KEY(FooTabHelper)
+// int FooTabHelper::kUserDataKey;
 //
 template <typename T>
 class WebContentsUserData : public base::SupportsUserData::Data {
@@ -31,33 +32,18 @@ class WebContentsUserData : public base::SupportsUserData::Data {
   // If an instance is already attached, does nothing.
   static void CreateForWebContents(content::WebContents* contents) {
     if (!FromWebContents(contents))
-      contents->SetUserData(&kLocatorKey, new T(contents));
+      contents->SetUserData(&T::kUserDataKey, new T(contents));
   }
 
   // Retrieves the instance of type T that was attached to the specified
   // WebContents (via CreateForWebContents above) and returns it. If no instance
   // of the type was attached, returns NULL.
   static T* FromWebContents(content::WebContents* contents) {
-    return static_cast<T*>(contents->GetUserData(&kLocatorKey));
+    return static_cast<T*>(contents->GetUserData(&T::kUserDataKey));
   }
   static const T* FromWebContents(const content::WebContents* contents) {
-    return static_cast<const T*>(contents->GetUserData(&kLocatorKey));
+    return static_cast<const T*>(contents->GetUserData(&T::kUserDataKey));
   }
-
-  // The user data key.
-  static int kLocatorKey;
 };
 
-// The macro to define the locator key. This key must be defined in the .cc file
-// of the tab helper otherwise different instances for different template types
-// will be collapsed by the Visual Studio linker.
-//
-// The "= 0" is surprising, but is required to effect a definition rather than
-// a declaration. Without it, this would be merely a declaration of a template
-// specialization. (C++98: 14.7.3.15; C++11: 14.7.3.13)
-//
-#define DEFINE_WEB_CONTENTS_USER_DATA_KEY(TYPE) \
-template<>                                      \
-int WebContentsUserData<TYPE>::kLocatorKey = 0;
-
 #endif  // CHROME_BROWSER_COMMON_WEB_CONTENTS_USER_DATA_H_
diff --git a/chrome/browser/common/web_contents_user_data_unittest.cc b/chrome/browser/common/web_contents_user_data_unittest.cc
index 1ee3a6a..cb35bac 100644
--- a/chrome/browser/common/web_contents_user_data_unittest.cc
+++ b/chrome/browser/common/web_contents_user_data_unittest.cc
@@ -11,12 +11,15 @@
 #include "content/public/test/web_contents_tester.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+namespace {
+
 class WebContentsAttachedClass1
     : public WebContentsUserData<WebContentsAttachedClass1> {
  public:
   virtual ~WebContentsAttachedClass1() {}
  private:
   explicit WebContentsAttachedClass1(content::WebContents* contents) {}
+  static int kUserDataKey;
   friend class WebContentsUserData<WebContentsAttachedClass1>;
 };
 
@@ -26,11 +29,14 @@ class WebContentsAttachedClass2
   virtual ~WebContentsAttachedClass2() {}
  private:
   explicit WebContentsAttachedClass2(content::WebContents* contents) {}
+  static int kUserDataKey;
   friend class WebContentsUserData<WebContentsAttachedClass2>;
 };
 
-DEFINE_WEB_CONTENTS_USER_DATA_KEY(WebContentsAttachedClass1)
-DEFINE_WEB_CONTENTS_USER_DATA_KEY(WebContentsAttachedClass2)
+int WebContentsAttachedClass1::kUserDataKey;
+int WebContentsAttachedClass2::kUserDataKey;
+
+}  // namespace
 
 typedef ChromeRenderViewHostTestHarness WebContentsUserDataTest;