Makes the OfflinePageBridge.getAllPages method asynchronous.

chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageStorageSpacePolicy.java

Index: chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageStorageSpacePolicy.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageStorageSpacePolicy.java b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageStorageSpacePolicy.java
index 68732e6b33d9cb195f9778636c00df0a89d74af9..756e3f4b5142615aa1f955d2c353b7ffd691d914 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageStorageSpacePolicy.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/offlinepages/OfflinePageStorageSpacePolicy.java
@@ -8,6 +8,9 @@ import java.util.List;
 
 /**
  * Manages the storage space policy for offline pages.
+ *
+ * When created, it records the size on disk that is being used, this value never changes after
+ * creation so make a new OfflinePageStorageSpacePolicy whenever a new measurement is desired.
  */
 public class OfflinePageStorageSpacePolicy {
     /**
@@ -19,19 +22,47 @@ public class OfflinePageStorageSpacePolicy {
      */
     private static final long MINIMUM_CLEANUP_SIZE_BYTES = 5 * (1 << 20); // 5MB
 
-    private OfflinePageBridge mOfflinePageBridge;
+    private long mSizeOfAllPages;
+    private long mSizeOfPagesToCleanUp;
 
     /**
-     * @param offlinePageBridge An object to access offline page functionality.
+     * Callback that is fired when a policy object is ready after calling |create|.
+     */
+    public interface CreateCallback {
+        public void onCreateDone(OfflinePageStorageSpacePolicy policy);
+    }
+
+    /**
+     * Asynchronously creates an OffinePageStorageSpacePolicy which is prefilled with information
+     * about the state of the disk usage of Offline Pages.
      */
-    public OfflinePageStorageSpacePolicy(OfflinePageBridge offlinePageBridge) {
+    public static void create(
+            final OfflinePageBridge offlinePageBridge, final CreateCallback callback) {
         assert offlinePageBridge != null;
-        mOfflinePageBridge = offlinePageBridge;
+        offlinePageBridge.getAllPages(new OfflinePageBridge.GetAllPagesCallback() {
+            @Override
+            public void onGetAllPagesDone(List<OfflinePageItem> allPages) {
+                callback.onCreateDone(
+                        new OfflinePageStorageSpacePolicy(offlinePageBridge, allPages));
+            }
+        });
+    }
+
+    /**
+     * Creates a policy object with the given list of offline pages.
+     *
+     * @param offlinePageBridge An object to access offline page functionality.
+     * @param offlinePages The list of all offline pages.
+     */
+    private OfflinePageStorageSpacePolicy(
+            OfflinePageBridge offlinePageBridge, List<OfflinePageItem> offlinePages) {
+        mSizeOfAllPages = offlinePageBridge.getTotalSize(offlinePages);
+        mSizeOfPagesToCleanUp = getSizeOfPagesToCleanUp();
     }
 
     /** @return Whether there exists offline pages that could be cleaned up to make space. */
     public boolean hasPagesToCleanUp() {
-        return getSizeOfPagesToCleanUp() > 0;
+        return mSizeOfPagesToCleanUp > 0;
     }
 
     /**
@@ -45,18 +76,10 @@ public class OfflinePageStorageSpacePolicy {
 
     /** @return Total size, in bytes, of all saved pages. */
     public long getSizeOfAllPages() {
-        return getTotalSize(mOfflinePageBridge.getAllPages());
+        return mSizeOfAllPages;
     }
 
     private long getSizeOfPagesToCleanUp() {
-        return getTotalSize(mOfflinePageBridge.getPagesToCleanUp());
-    }
-
-    private long getTotalSize(List<OfflinePageItem> offlinePages) {
-        long totalSize = 0;
-        for (OfflinePageItem page : offlinePages) {
-            totalSize += page.getFileSize();
-        }
-        return totalSize;
+        return mSizeOfPagesToCleanUp;
     }
 }