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

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

Index: content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
diff --git a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
index 40661f1caf9c7d53fcc92e2032619dec8ccb6767..dd5d22bbef217f6d7be4dac10591f4731982901d 100644
--- a/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
+++ b/content/public/android/java/src/org/chromium/content/browser/ContentViewCore.java
@@ -1456,8 +1456,10 @@ 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);
@@ -1641,6 +1643,8 @@ 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));
@@ -2116,7 +2120,7 @@ public class ContentViewCore
     }
 
     public void clearSslPreferences() {
-        nativeClearSslPreferences(mNativeContentViewCore);
+        if (mNativeContentViewCore != 0) nativeClearSslPreferences(mNativeContentViewCore);
     }
 
     private boolean isSelectionHandleShowing() {