Safety check has been added before calling native JNI functions to prevent random crashes.

BUG=

Review URL: https://codereview.chromium.org/269443003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@268016 0039d316-1c4b-4281-b951-d872f2087c98

AUTHORS

@@ -16,6 +16,7 @@ Adam Treat <adam.treat@samsung.com>
 Adenilson Cavalcanti <a.cavalcanti@partner.samsung.com>
 Aditya Bhargava <heuristicist@gmail.com>
 Ajay Berwal <ajay.berwal@samsung.com>
+Ajith Kumar V <ajith.v@samsung.com>
 Alex Gartrell <agartrell@cmu.edu>
 Alex Scheele <alexscheele@gmail.com>
 Alexander Sulfrian <alexander@sulfrian.net>

content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java

@@ -1468,8 +1468,10 @@ public class ContentViewCore
         TraceEvent.begin();
 
         if (newConfig.keyboard != Configuration.KEYBOARD_NOKEYS) {
-            mImeAdapter.attach(nativeGetNativeImeAdapter(mNativeContentViewCore),
-                    ImeAdapter.getTextInputTypeNone());
+            if (mNativeContentViewCore != 0) {
+                mImeAdapter.attach(nativeGetNativeImeAdapter(mNativeContentViewCore),
+                        ImeAdapter.getTextInputTypeNone());
+            }
             mInputMethodManagerWrapper.restartInput(mContainerView);
         }
         mContainerViewInternals.super_onConfigurationChanged(newConfig);
@@ -1655,6 +1657,8 @@ public class ContentViewCore
         if ((event.getSource() & InputDevice.SOURCE_CLASS_POINTER) != 0) {
             switch (event.getAction()) {
                 case MotionEvent.ACTION_SCROLL:
+                    if (mNativeContentViewCore == 0) return false;
+
                     nativeSendMouseWheelEvent(mNativeContentViewCore, event.getEventTime(),
                             event.getX(), event.getY(),
                             event.getAxisValue(MotionEvent.AXIS_VSCROLL));
@@ -2131,7 +2135,7 @@ public class ContentViewCore
     }
 
     public void clearSslPreferences() {
-        nativeClearSslPreferences(mNativeContentViewCore);
+        if (mNativeContentViewCore != 0) nativeClearSslPreferences(mNativeContentViewCore);
     }
 
     private boolean isSelectionHandleShowing() {