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..7eaff37040d7bc60feb6680979a3467d03294f42 100644
--- a/base/message_loop/message_pump_android.h
+++ b/base/message_loop/message_pump_android.h
@@ -12,6 +12,7 @@
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/message_loop/message_pump.h"
+#include "base/synchronization/waitable_event.h"
 
 namespace base {
 
@@ -31,12 +32,26 @@ class BASE_EXPORT MessagePumpForUI : public MessagePump {
   void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
 
   virtual void Start(Delegate* delegate);
+  void StartForTesting(Delegate* delegate, 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_; }
+
+  void NotifyTestDone();
 
   static bool RegisterBindings(JNIEnv* env);
 
  private:
   RunLoop* run_loop_;
   base::android::ScopedJavaGlobalRef<jobject> system_message_handler_obj_;
+  bool should_abort_;
+  // An event that is triggered when we catch a certain test exception in
+  // SystemMessageHandler, this event is only used in tests.
+  WaitableEvent* test_event_;
 
   DISALLOW_COPY_AND_ASSIGN(MessagePumpForUI);
 };