Take a screenshot in maximize mode when volume down and power are pressed.

ash/wm/maximize_mode/maximize_mode_controller_unittest.cc

Index: ash/wm/maximize_mode/maximize_mode_controller_unittest.cc
diff --git a/ash/wm/maximize_mode/maximize_mode_controller_unittest.cc b/ash/wm/maximize_mode/maximize_mode_controller_unittest.cc
index d619fd5239dd9885cfa172987272bdb5893686e3..9e84bda7449a3f8859d59ff824ad269d8ce2613a 100644
--- a/ash/wm/maximize_mode/maximize_mode_controller_unittest.cc
+++ b/ash/wm/maximize_mode/maximize_mode_controller_unittest.cc
@@ -9,6 +9,7 @@
 #include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "ash/test/display_manager_test_api.h"
+#include "ash/test/test_screenshot_delegate.h"
 #include "ui/aura/test/event_generator.h"
 #include "ui/events/event_handler.h"
 #include "ui/gfx/vector3d_f.h"
@@ -327,6 +328,34 @@ TEST_F(MaximizeModeControllerTest, BlocksKeyboard) {
   counter.reset();
 }
 
+#if defined(OS_CHROMEOS)
+// Tests that a screenshot can be taken in maximize mode by holding volume down
+// and pressing power.
+TEST_F(MaximizeModeControllerTest, Screenshot) {
+  aura::Window* root = Shell::GetPrimaryRootWindow();
+  aura::test::EventGenerator event_generator(root, root);
+  test::TestScreenshotDelegate* delegate = GetScreenshotDelegate();
+  delegate->set_can_take_screenshot(true);
+
+  // Open up 270 degrees.
+  TriggerAccelerometerUpdate(gfx::Vector3dF(0.0f, 0.0f, 1.0f),
+                             gfx::Vector3dF(1.0f, 0.0f, 0.0f));
+  ASSERT_TRUE(IsMaximizeModeStarted());
+
+  // Pressing power alone does not take a screenshot.
+  event_generator.PressKey(ui::VKEY_POWER, 0);
+  event_generator.ReleaseKey(ui::VKEY_POWER, 0);
+  EXPECT_EQ(0, delegate->handle_take_screenshot_count());
+
+  // Holding volume down and pressing power takes a screenshot.
+  event_generator.PressKey(ui::VKEY_VOLUME_DOWN, 0);
+  event_generator.PressKey(ui::VKEY_POWER, 0);
+  event_generator.ReleaseKey(ui::VKEY_POWER, 0);
+  EXPECT_EQ(1, delegate->handle_take_screenshot_count());
+  event_generator.ReleaseKey(ui::VKEY_VOLUME_DOWN, 0);
+}
+#endif
+
 TEST_F(MaximizeModeControllerTest, LaptopTest) {
   // Feeds in sample accelerometer data and verifies that there are no
   // transitions into touchview / maximize mode while shaking the device around