Fix use after free for cached_displays_.

ui/display/manager/chromeos/test/test_native_display_delegate.cc

 // Copyright 2014 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.
 
 #include "ui/display/manager/chromeos/test/test_native_display_delegate.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "ui/display/manager/chromeos/test/action_logger.h"
 #include "ui/display/types/display_mode.h"
+#include "ui/display/types/native_display_observer.h"
 
 namespace ui {
 namespace test {
 
 TestNativeDisplayDelegate::TestNativeDisplayDelegate(ActionLogger* log)
     : max_configurable_pixels_(0),
       get_hdcp_expectation_(true),
       set_hdcp_expectation_(true),
       hdcp_state_(HDCP_STATE_UNDESIRED),
       run_async_(false),
@@ skipping 32 matching lines @@
 void TestNativeDisplayDelegate::SetBackgroundColor(uint32_t color_argb) {
   log_->AppendAction(GetBackgroundAction(color_argb));
 }
 
 void TestNativeDisplayDelegate::ForceDPMSOn() {
   log_->AppendAction(kForceDPMS);
 }
 
 void TestNativeDisplayDelegate::GetDisplays(
     const GetDisplaysCallback& callback) {
+  // This mimics the behavior of Ozone DRM when new display state arrives.
+  for (NativeDisplayObserver& observer : observers_)
+    observer.OnDisplaySnapshotsInvalidated();
+
   if (run_async_) {
     base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE, base::Bind(callback, outputs_));
   } else {
     callback.Run(outputs_);
   }
 }
 
 void TestNativeDisplayDelegate::AddMode(const DisplaySnapshot& output,
                                         const DisplayMode* mode) {
@@ skipping 62 matching lines @@
 bool TestNativeDisplayDelegate::SetColorCorrection(
     const ui::DisplaySnapshot& output,
     const std::vector<GammaRampRGBEntry>& degamma_lut,
     const std::vector<GammaRampRGBEntry>& gamma_lut,
     const std::vector<float>& correction_matrix) {
   log_->AppendAction(SetColorCorrectionAction(output, degamma_lut, gamma_lut,
                                               correction_matrix));
   return true;
 }
 
-void TestNativeDisplayDelegate::AddObserver(NativeDisplayObserver* observer) {}
+void TestNativeDisplayDelegate::AddObserver(NativeDisplayObserver* observer) {
+  observers_.AddObserver(observer);
+}
 
 void TestNativeDisplayDelegate::RemoveObserver(
-    NativeDisplayObserver* observer) {}
+    NativeDisplayObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
 
 display::FakeDisplayController*
 TestNativeDisplayDelegate::GetFakeDisplayController() {
   return nullptr;
 }
 
 }  // namespace test
 }  // namespace ui