Fix screen flicker when resizing CRD window in split-screen mode

remoting/android/java/src/org/chromium/chromoting/DesktopCanvas.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chromoting;
 
 import android.graphics.Matrix;
 import android.graphics.PointF;
 import android.graphics.Rect;
 import android.graphics.RectF;
@@ skipping 104 matching lines @@
         if (parameter.softInputMethodVisible) {
             mSystemUiScreenRect.set(
                     parameter.left, parameter.top, parameter.right, parameter.bottom);
 
             stopOffsetReductionAnimation();
         } else {
             mSystemUiScreenRect.setEmpty();
             startOffsetReductionAnimation();
         }
 
-        repositionImage();
+        if (mRenderData.initialized()) {
+            // The viewport center may have changed so update the position to reflect the new value.
+            repositionImage();
+        }
     }
 
     public void adjustViewportForSystemUi(boolean adjustViewportForSystemUi) {
         mAdjustViewportSizeForSystemUi = adjustViewportForSystemUi;
 
-        // The viewport center may have changed so reposition the image to reflect the new value.
-        repositionImage();
+        if (mRenderData.initialized()) {
+            // The viewport center may have changed so update the position to reflect the new value.
+            repositionImage();
+        }
     }
 
     /** Resizes the image by zooming it such that the image is displayed without borders. */
     public void resizeImageToFitScreen() {
         // Protect against being called before the image has been initialized.
         if (mRenderData.imageWidth == 0 || mRenderData.imageHeight == 0) {
             return;
         }
 
         float widthRatio = (float) mRenderData.screenWidth / mRenderData.imageWidth;
@@ skipping 298 matching lines @@
     }
 
     /**
      * Stops an existing offset reduction animation.
      */
     private void stopOffsetReductionAnimation() {
         // Setting this value this null will prevent it from continuing to execute.
         mFrameRenderedCallback = null;
     }
 }