Properly throw java exceptions from shouldOverrideUrlLoading

base/message_loop/message_pump_android.h

Index: base/message_loop/message_pump_android.h
diff --git a/base/message_loop/message_pump_android.h b/base/message_loop/message_pump_android.h
index 795bd5e79ee69569347d3c0c57522c3717c892ee..e4adaf646b6625666a6abd29de377381ec8e9a62 100644
--- a/base/message_loop/message_pump_android.h
+++ b/base/message_loop/message_pump_android.h
@@ -15,8 +15,13 @@
 
 namespace base {
 
+namespace android {
+class JavaMessageHandlerFactory;
+}
+
 class RunLoop;
 class TimeTicks;
+class WaitableEvent;
 
 // This class implements a MessagePump needed for TYPE_UI MessageLoops on
 // OS_ANDROID platform.
@@ -31,12 +36,25 @@ class BASE_EXPORT MessagePumpForUI : public MessagePump {
   void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
 
   virtual void Start(Delegate* delegate);
+  void StartForUnitTest(Delegate* delegate,
+                        base::android::JavaMessageHandlerFactory* factory,
+                        WaitableEvent* test_done_event);
+
+  // We call Abort when there is a pending JNI exception, meaning that the
+  // current thread will crash when we return to Java.
+  // We can't call any JNI-methods before returning to Java as we would then
+  // cause a native crash (instead of the original Java crash).
+  void Abort() { should_abort_ = true; }
+  bool ShouldAbort() const { return should_abort_; }
 
   static bool RegisterBindings(JNIEnv* env);
 
  private:
+  JNIEnv* StartInternal();
+
   RunLoop* run_loop_;
   base::android::ScopedJavaGlobalRef<jobject> system_message_handler_obj_;
+  bool should_abort_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpForUI);
 };