Fix a crash about editing an nonexistent bookmark

chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkEditActivity.java

Index: chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkEditActivity.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkEditActivity.java b/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkEditActivity.java
index a925f57b3bc1536614d9d640ad6d68b6d9a30f3d..d436748a5a6ebda4acfb37e6db4be276dc3cdb74 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkEditActivity.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/enhancedbookmarks/EnhancedBookmarkEditActivity.java
@@ -51,7 +51,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
         VISIT,
     }
 
-    private EnhancedBookmarksModel mEnhancedBookmarksModel;
+    private EnhancedBookmarksModel mModel;
     private BookmarkId mBookmarkId;
     private EmptyAlertEditText mTitleEditText;
     private EmptyAlertEditText mUrlEditText;
@@ -76,7 +76,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
         @Override
         public void bookmarkNodeMoved(BookmarkItem oldParent, int oldIndex, BookmarkItem newParent,
                 int newIndex) {
-            BookmarkId movedBookmark = mEnhancedBookmarksModel.getChildAt(newParent.getId(),
+            BookmarkId movedBookmark = mModel.getChildAt(newParent.getId(),
                     newIndex);
             if (movedBookmark.equals(mBookmarkId)) {
                 mFolderTextView.setText(newParent.getTitle());
@@ -86,14 +86,14 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
         @Override
         public void bookmarkNodeChanged(BookmarkItem node) {
             if (mBookmarkId.equals(node.getId()) || node.getId().equals(
-                    mEnhancedBookmarksModel.getBookmarkById(mBookmarkId).getParentId())) {
+                    mModel.getBookmarkById(mBookmarkId).getParentId())) {
                 updateViewContent();
             }
         }
 
         @Override
         public void bookmarkModelChanged() {
-            if (mEnhancedBookmarksModel.doesBookmarkExist(mBookmarkId)) {
+            if (mModel.doesBookmarkExist(mBookmarkId)) {
                 updateViewContent();
             } else {
                 Log.wtf(TAG, "The bookmark was deleted somehow during bookmarkModelChange!",
@@ -110,11 +110,15 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
         int title = OfflinePageUtils.getStringId(R.string.edit_bookmark);
         setTitle(title);
         EnhancedBookmarkUtils.setTaskDescriptionInDocumentMode(this, getString(title));
-        mEnhancedBookmarksModel = new EnhancedBookmarksModel();
+        mModel = new EnhancedBookmarksModel();
         mBookmarkId = BookmarkId.getBookmarkIdFromString(
                 getIntent().getStringExtra(INTENT_BOOKMARK_ID));
-        mEnhancedBookmarksModel.addObserver(mBookmarkModelObserver);
-        assert mEnhancedBookmarksModel.getBookmarkById(mBookmarkId).isEditable();
+        mModel.addObserver(mBookmarkModelObserver);
+        BookmarkItem item = mModel.getBookmarkById(mBookmarkId);
+        if (!mModel.doesBookmarkExist(mBookmarkId) || item == null) {
+            finish();
+            return;
+        }
 
         setContentView(R.layout.eb_edit);
         mTitleEditText = (EmptyAlertEditText) findViewById(R.id.title_text);
@@ -130,7 +134,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
         });
 
         if (OfflinePageBridge.isEnabled() && OfflinePageBridge.canSavePage(
-                mEnhancedBookmarksModel.getBookmarkById(mBookmarkId).getUrl())) {
+                mModel.getBookmarkById(mBookmarkId).getUrl())) {
             mOfflinePageModelObserver = new OfflinePageModelObserver() {
                 @Override
                 public void offlinePageDeleted(BookmarkId bookmarkId) {
@@ -140,7 +144,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
                 }
             };
 
-            mEnhancedBookmarksModel.getOfflinePageBridge().addObserver(mOfflinePageModelObserver);
+            mModel.getOfflinePageBridge().addObserver(mOfflinePageModelObserver);
             // Make offline page section visible and find controls.
             findViewById(R.id.offline_page_group).setVisibility(View.VISIBLE);
             getIntent().setExtrasClassLoader(WebContents.class.getClassLoader());
@@ -156,18 +160,19 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
     }
 
     private void updateViewContent() {
-        BookmarkItem bookmarkItem = mEnhancedBookmarksModel.getBookmarkById(mBookmarkId);
+        BookmarkItem bookmarkItem = mModel.getBookmarkById(mBookmarkId);
 
         if (!TextUtils.equals(mTitleEditText.getTrimmedText(), bookmarkItem.getTitle())) {
             mTitleEditText.setText(bookmarkItem.getTitle());
         }
-        String folderTitle = mEnhancedBookmarksModel.getBookmarkTitle(bookmarkItem.getParentId());
+        String folderTitle = mModel.getBookmarkTitle(bookmarkItem.getParentId());
         if (!TextUtils.equals(mFolderTextView.getText(), folderTitle)) {
             mFolderTextView.setText(folderTitle);
         }
         if (!TextUtils.equals(mUrlEditText.getTrimmedText(), bookmarkItem.getUrl())) {
             mUrlEditText.setText(bookmarkItem.getUrl());
         }
+        mTitleEditText.setEnabled(bookmarkItem.isEditable());
         mUrlEditText.setEnabled(bookmarkItem.isUrlEditable());
         mFolderTextView.setEnabled(bookmarkItem.isMovable());
     }
@@ -188,7 +193,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
             // Log added for detecting delete button double clicking.
             Log.i(TAG, "Delete button pressed by user! isFinishing() == " + isFinishing());
 
-            mEnhancedBookmarksModel.deleteBookmark(mBookmarkId);
+            mModel.deleteBookmark(mBookmarkId);
             finish();
             return true;
         } else if (item.getItemId() == android.R.id.home) {
@@ -200,26 +205,26 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
 
     @Override
     protected void onStop() {
-        if (mEnhancedBookmarksModel.doesBookmarkExist(mBookmarkId)) {
+        if (mModel.doesBookmarkExist(mBookmarkId)) {
             final String originalUrl =
-                    mEnhancedBookmarksModel.getBookmarkById(mBookmarkId).getUrl();
+                    mModel.getBookmarkById(mBookmarkId).getUrl();
             final String title = mTitleEditText.getTrimmedText();
             final String url = mUrlEditText.getTrimmedText();
 
             if (!mTitleEditText.isEmpty()) {
-                mEnhancedBookmarksModel.setBookmarkTitle(mBookmarkId, title);
+                mModel.setBookmarkTitle(mBookmarkId, title);
             }
 
             if (!mUrlEditText.isEmpty()
-                    && mEnhancedBookmarksModel.getBookmarkById(mBookmarkId).isUrlEditable()) {
+                    && mModel.getBookmarkById(mBookmarkId).isUrlEditable()) {
                 String fixedUrl = UrlUtilities.fixupUrl(url);
                 if (fixedUrl != null && !fixedUrl.equals(originalUrl)) {
                     boolean hasOfflinePage = OfflinePageBridge.isEnabled()
-                            && mEnhancedBookmarksModel.getOfflinePageBridge()
+                            && mModel.getOfflinePageBridge()
                                     .getPageByBookmarkId(mBookmarkId) != null;
                     RecordHistogram.recordBooleanHistogram(
                             "OfflinePages.Edit.BookmarkUrlChangedForOfflinePage", hasOfflinePage);
-                    mEnhancedBookmarksModel.setBookmarkUrl(mBookmarkId, fixedUrl);
+                    mModel.setBookmarkUrl(mBookmarkId, fixedUrl);
                 }
             }
         }
@@ -231,12 +236,12 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
     protected void onDestroy() {
         recordOfflineButtonAction(false);
         if (OfflinePageBridge.isEnabled()) {
-            mEnhancedBookmarksModel.getOfflinePageBridge().removeObserver(
+            mModel.getOfflinePageBridge().removeObserver(
                     mOfflinePageModelObserver);
         }
-        mEnhancedBookmarksModel.removeObserver(mBookmarkModelObserver);
-        mEnhancedBookmarksModel.destroy();
-        mEnhancedBookmarksModel = null;
+        mModel.removeObserver(mBookmarkModelObserver);
+        mModel.destroy();
+        mModel = null;
         super.onDestroy();
     }
 
@@ -245,14 +250,14 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
 
         // It is possible that callback arrives after the activity was dismissed.
         // See http://crbug.com/566939
-        if (mEnhancedBookmarksModel == null) return;
+        if (mModel == null) return;
 
-        mEnhancedBookmarksModel.getOfflinePageBridge().checkOfflinePageMetadata();
+        mModel.getOfflinePageBridge().checkOfflinePageMetadata();
 
         Button saveRemoveVisitButton = (Button) findViewById(R.id.offline_page_save_remove_button);
         TextView offlinePageInfoTextView = (TextView) findViewById(R.id.offline_page_info_text);
 
-        OfflinePageItem offlinePage = mEnhancedBookmarksModel.getOfflinePageBridge()
+        OfflinePageItem offlinePage = mModel.getOfflinePageBridge()
                 .getPageByBookmarkId(mBookmarkId);
         if (offlinePage != null) {
             // Offline page exists. Show information and button to remove.
@@ -282,7 +287,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
             @Override
             public void onClick(View v) {
                 recordOfflineButtonAction(true);
-                mEnhancedBookmarksModel.getOfflinePageBridge().deletePage(
+                mModel.getOfflinePageBridge().deletePage(
                         mBookmarkId, new DeletePageCallback() {
                             @Override
                             public void onDeletePageDone(int deletePageResult) {
@@ -303,7 +308,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
             @Override
             public void onClick(View v) {
                 recordOfflineButtonAction(true);
-                mEnhancedBookmarksModel.getOfflinePageBridge().savePage(
+                mModel.getOfflinePageBridge().savePage(
                         mWebContents, mBookmarkId, new SavePageCallback() {
                             @Override
                             public void onSavePageDone(int savePageResult, String url) {
@@ -333,7 +338,7 @@ public class EnhancedBookmarkEditActivity extends EnhancedBookmarkActivityBase {
         // TODO(kkimlabs): Refactor this out to handle the intent in ChromeActivity.
         if (DeviceFormFactor.isTablet(this)) {
             EnhancedBookmarkUtils.openBookmark(
-                    mEnhancedBookmarksModel, this, mBookmarkId, LaunchLocation.BOOKMARK_EDITOR);
+                    mModel, this, mBookmarkId, LaunchLocation.BOOKMARK_EDITOR);
         } else {
             Intent intent = new Intent();
             intent.putExtra(