Add a one-time notice about other forms of browsing history.

chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java

Index: chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java b/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
index 138850528e849021be56a42698744cfef6088bea..009c32111a052ee82010f27d47236bf2242826fc 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/preferences/privacy/ClearBrowsingDataPreferences.java
@@ -274,14 +274,30 @@ public class ClearBrowsingDataPreferences extends PreferenceFragment
             option.getDataType());
     }
 
-    // Called when "clear browsing data" completes.
-    // Implements the ChromePreferences.OnClearBrowsingDataListener interface.
+    private OtherFormsOfHistoryDialogFragment mDialogAboutOtherFormsOfBrowsingHistory;
+    private boolean mDialogAboutOtherFormsOfBrowsingHistoryEnabled;

[gone, 2016/04/07 21:05:26]

Group these new member fields with the other ones above all of the class methods
and below the static inner classes.  Doesn't make sense to have these randomly
located in the middle of a class where they would be missed during
initialization.

[msramek, 2016/04/08 11:20:42]

Done.

+
+    /**
+     * Called when clearing browsing data completes.
+     * Implements the ChromePreferences.OnClearBrowsingDataListener interface.
+     */
     @Override
     public void onBrowsingDataCleared() {
         if (getActivity() == null) return;
 
-        dismissProgressDialog();
-        getActivity().finish();
+        // If the user deleted their browsing history, the dialog about other forms of history
+        // is enabled, and it has never been shown before, show it. Otherwise, just close this
+        // preference screen.
+        if (getSelectedOptions().contains(DialogOption.CLEAR_HISTORY)
+                && mDialogAboutOtherFormsOfBrowsingHistoryEnabled
+                && !OtherFormsOfHistoryDialogFragment.wasDialogShown(getActivity())) {
+            mDialogAboutOtherFormsOfBrowsingHistory =
+                    OtherFormsOfHistoryDialogFragment.show(getActivity());
+            dismissProgressDialog();
+        } else {
+            dismissProgressDialog();
+            getActivity().finish();
+        }
     }
 
     @Override
@@ -455,4 +471,22 @@ public class ClearBrowsingDataPreferences extends PreferenceFragment
         google_summary.setSummary(
                 R.string.clear_browsing_data_footnote_signed_and_other_forms_of_history);
     }
+
+    /**
+     * Enables the dialog about other forms of browsing history that will be shown to the user
+     * after deleting their Chrome history. To be called by the web history service when the
+     * conditions for showing the dialog are met.
+     */
+    @VisibleForTesting
+    public void enableDialogAboutOtherFormsOfBrowsingHistory() {

[gone, 2016/04/07 21:05:26]

...BrowsingHistoryForTests() to make it explicit.

[msramek, 2016/04/08 11:20:42]

They are currently used only in tests, because there is no connection to the
backend, but this method will be called from the backend in the followup CL.

+        mDialogAboutOtherFormsOfBrowsingHistoryEnabled = true;

[gone, 2016/04/07 21:05:26]

mIsDialogAboutOtherFormsOfBrowsingHistoryEnabled?

[msramek, 2016/04/08 11:20:42]

Done.

+    }
+
+    /**
+     * Used only to access the dialog about other forms of browsing history from tests.
+     */
+    @VisibleForTesting
+    OtherFormsOfHistoryDialogFragment getDialogAboutOtherFormsOfBrowsingHistory() {

[gone, 2016/04/07 21:05:26]

...BrowsingHistoryForTests()

[msramek, 2016/04/08 11:20:42]

Ditto as above.

+        return mDialogAboutOtherFormsOfBrowsingHistory;
+    }
 }