Revert of [Reland] Refactor WebappRegistry into a singleton instance.

chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
index ca67c875eaf62a34432c43bb5853044c45e3dc44..7022ef318d8d07909215a9e15830a78a08f042f5 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/webapps/WebappActivity.java
@@ -60,6 +60,8 @@
 
     protected WebappInfo mWebappInfo;
 
+    private boolean mOldWebappCleanupStarted;
+
     private ViewGroup mSplashScreen;
     private WebappUrlBar mUrlBar;
 
@@ -124,23 +126,7 @@
     @Override
     public void preInflationStartup() {
         WebappInfo info = WebappInfo.create(getIntent());
-
-        String id = "";
-        if (info != null) {
-            mWebappInfo = info;
-            id = info.id();
-        }
-
-        // Initialize the WebappRegistry and warm up the shared preferences for this web app. No-ops
-        // if the registry and this web app are already initialized. Must override Strict Mode to
-        // avoid a violation.
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskReads();
-        try {
-            WebappRegistry.getInstance();
-            WebappRegistry.warmUpSharedPrefsForId(id);
-        } finally {
-            StrictMode.setThreadPolicy(oldPolicy);
-        }
+        if (info != null) mWebappInfo = info;
 
         ScreenOrientationProvider.lockOrientation((byte) mWebappInfo.orientation(), this);
         super.preInflationStartup();
@@ -209,6 +195,13 @@
             updateTaskDescription();
         }
         super.onResume();
+
+        // Kick off the old web app cleanup (if we haven't already) now that we have queued the
+        // current web app's storage to be opened.
+        if (!mOldWebappCleanupStarted) {
+            WebappRegistry.unregisterOldWebapps(System.currentTimeMillis());
+            mOldWebappCleanupStarted = true;
+        }
     }
 
     @Override
@@ -269,20 +262,25 @@
     }
 
     protected void initializeSplashScreenWidgets(final int backgroundColor) {
-        WebappDataStorage storage =
-                WebappRegistry.getInstance().getWebappDataStorage(mWebappInfo.id());
-        if (storage == null) {
-            onStorageIsNull(backgroundColor);
-            return;
-        }
-
-        updateStorage(storage);
-        storage.getSplashScreenImage(new WebappDataStorage.FetchCallback<Bitmap>() {
-            @Override
-            public void onDataRetrieved(Bitmap splashImage) {
-                initializeSplashScreenWidgets(backgroundColor, splashImage);
-            }
-        });
+        WebappRegistry.getWebappDataStorage(
+                mWebappInfo.id(), new WebappRegistry.FetchWebappDataStorageCallback() {
+                    @Override
+                    public void onWebappDataStorageRetrieved(WebappDataStorage storage) {
+                        if (storage == null) {
+                            onStorageIsNull(backgroundColor);
+                            return;
+                        }
+                        updateStorage(storage);
+
+                        // Retrieve the splash image if it exists.
+                        storage.getSplashScreenImage(new WebappDataStorage.FetchCallback<Bitmap>() {
+                            @Override
+                            public void onDataRetrieved(Bitmap splashImage) {
+                                initializeSplashScreenWidgets(backgroundColor, splashImage);
+                            }
+                        });
+                    }
+                });
     }
 
     protected void onStorageIsNull(int backgroundColor) {}