No longer register app window placement preference keys on the fly.

chrome/browser/ui/browser_window_state.h

Index: chrome/browser/ui/browser_window_state.h
diff --git a/chrome/browser/ui/browser_window_state.h b/chrome/browser/ui/browser_window_state.h
index ec5e7ff1ea51f3f0a07e0687170d06b33a7eac6d..b951d386c5aad61de8823180394612c88cc85e31 100644
--- a/chrome/browser/ui/browser_window_state.h
+++ b/chrome/browser/ui/browser_window_state.h
@@ -7,17 +7,37 @@
 
 #include <string>
 
+#include "base/memory/scoped_ptr.h"
+#include "base/prefs/scoped_user_pref_update.h"
 #include "ui/base/ui_base_types.h"
 
 class Browser;
 
+namespace base {
+class DictionaryValue;
+}
+
 namespace gfx {
 class Rect;
 }
 
+class PrefService;
+
 namespace chrome {
 
-std::string GetWindowPlacementKey(const Browser* browser);
+std::string GetWindowName(const Browser* browser);
+// A "window placement dictionary" holds information about the size and location
+// of the window that is stored in the given PrefService. If the window_name
+// isn't the name of a registered preference it is assumed to be the name of an
+// app and the AppWindowPlacement key is used to find the app's dictionary.
+scoped_ptr<DictionaryPrefUpdate> GetWindowPlacementDictionaryReadWrite(
+    const std::string& window_name,
+    PrefService* prefs);
+// Returns NULL if the window corresponds to an app that doesn't have placement
+// information stored in the preferences system.
+const base::DictionaryValue* GetWindowPlacementDictionaryReadOnly(
+    const std::string& window_name,
+    PrefService* prefs);
 
 bool ShouldSaveWindowPlacement(const Browser* browser);