Fix ProGuard issues after recent NavigationController refactoring

Annotate several NavigationController methods used only in testing, and
remove a helper test function that is unused even in tests.

BUG=398263
NOTRY=true

Review URL: https://codereview.chromium.org/569343002

Cr-Commit-Position: refs/heads/master@{#294864}

content/public/android/java/src/org/chromium/content/browser/framehost/NavigationControllerImpl.java

@@ -8,6 +8,7 @@ import android.graphics.Bitmap;
 
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
+import org.chromium.base.VisibleForTesting;
 import org.chromium.content_public.browser.LoadUrlParams;
 import org.chromium.content_public.browser.NavigationController;
 import org.chromium.content_public.browser.NavigationEntry;
@@ -51,6 +52,7 @@ import org.chromium.content_public.browser.NavigationHistory;
     }
 
     @Override
+    @VisibleForTesting
     public boolean canGoToOffset(int offset) {
         return mNativeNavigationControllerAndroid != 0
                 && nativeCanGoToOffset(mNativeNavigationControllerAndroid, offset);
@@ -146,6 +148,7 @@ import org.chromium.content_public.browser.NavigationHistory;
     }
 
     @Override
+    @VisibleForTesting
     public void clearHistory() {
         if (mNativeNavigationControllerAndroid != 0) {
             nativeClearHistory(mNativeNavigationControllerAndroid);

content/public/test/android/javatests/src/org/chromium/content/browser/test/util/HistoryUtils.java

@@ -23,11 +23,11 @@ public class HistoryUtils {
     protected static final long WAIT_TIMEOUT_SECONDS = scaleTimeout(15);
 
     /**
-     * Calls {@link ContentViewCore#canGoBack()} on UI thread.
+     * Calls {@link NavigationController#canGoBack()} on UI thread.
      *
      * @param instrumentation an Instrumentation instance.
      * @param contentViewCore a ContentViewCore instance.
-     * @return result of {@link ContentViewCore#canGoBack()}
+     * @return result of {@link NavigationController#canGoBack()}
      * @throws Throwable
      */
     public static boolean canGoBackOnUiThread(Instrumentation instrumentation,
@@ -42,13 +42,13 @@ public class HistoryUtils {
     }
 
     /**
-     * Calls {@link ContentViewCore#canGoToOffset(int)} on UI thread.
+     * Calls {@link NavigationController#canGoToOffset(int)} on UI thread.
      *
      * @param instrumentation an Instrumentation instance.
      * @param contentViewCore a ContentViewCore instance.
      * @param offset The number of steps to go on the UI thread, with negative
      *      representing going back.
-     * @return result of {@link ContentViewCore#canGoToOffset(int)}
+     * @return result of {@link NavigationController#canGoToOffset(int)}
      * @throws Throwable
      */
     public static boolean canGoToOffsetOnUiThread(Instrumentation instrumentation,
@@ -63,11 +63,11 @@ public class HistoryUtils {
     }
 
     /**
-     * Calls {@link ContentViewCore#canGoForward()} on UI thread.
+     * Calls {@link NavigationController#canGoForward()} on UI thread.
      *
      * @param instrumentation an Instrumentation instance.
      * @param contentViewCore a ContentViewCore instance.
-     * @return result of {@link ContentViewCore#canGoForward()}
+     * @return result of {@link NavigationController#canGoForward()}
      * @throws Throwable
      */
     public static boolean canGoForwardOnUiThread(Instrumentation instrumentation,
@@ -82,7 +82,7 @@ public class HistoryUtils {
     }
 
     /**
-     * Calls {@link ContentViewCore#clearHistory()} on UI thread.
+     * Calls {@link NavigationController#clearHistory()} on UI thread.
      *
      * @param instrumentation an Instrumentation instance.
      * @param contentViewCore a ContentViewCore instance.
@@ -99,7 +99,7 @@ public class HistoryUtils {
     }
 
     /**
-     * Calls {@link ContentViewCore#getUrl()} on UI Thread to get the current URL.
+     * Calls {@link NavigationController#getUrl()} on UI Thread to get the current URL.
      *
      * @param instrumentation an Instrumentation instance.
      * @param contentViewCore a ContentViewCore instance.
@@ -117,32 +117,6 @@ public class HistoryUtils {
         });
     }
 
-    /**
-     * Performs navigation in the history on UI thread and waits until
-     * onPageFinished is called.
-     *
-     * @param instrumentation an Instrumentation instance.
-     * @param contentViewCore a ContentViewCore instance.
-     * @param onPageFinishedHelper the CallbackHelper instance associated with the onPageFinished
-     *                             callback of contentViewCore.
-     * @param offset
-     * @throws Throwable
-     */
-    public static void goToOffsetSync(Instrumentation instrumentation,
-            final WebContents webContents, CallbackHelper onPageFinishedHelper,
-            final int offset) throws Throwable {
-        int currentCallCount = onPageFinishedHelper.getCallCount();
-        instrumentation.runOnMainSync(new Runnable() {
-            @Override
-            public void run() {
-                webContents.getNavigationController().goToOffset(offset);
-            }
-        });
-
-        // Wait for onPageFinished event or timeout after 30s
-        onPageFinishedHelper.waitForCallback(currentCallCount, 1, 30, TimeUnit.SECONDS);
-    }
-
     /**
      * Goes back on UI thread and waits until onPageFinished is called or until
      * it times out.