Correcly Report CanEnterMaximizeMode on devices without accelerometers

ash/wm/maximize_mode/maximize_mode_controller_unittest.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 <math.h>
 
 #include "ash/wm/maximize_mode/maximize_mode_controller.h"
 
 #include "ash/ash_switches.h"
 #include "ash/display/display_manager.h"
@@ skipping 327 matching lines @@
                        kAccelerometerFullyOpenTestData[i * 6 + 3],
                        kAccelerometerFullyOpenTestData[i * 6 + 5]);
     lid.Scale(kMeanGravity);
     TriggerBaseAndLidUpdate(base, lid);
     // There are a lot of samples, so ASSERT rather than EXPECT to only generate
     // one failure rather than potentially hundreds.
     ASSERT_TRUE(IsMaximizeModeStarted());
   }
 }
 
+// Tests that when and empty accelerometer update is received for attaching as a
+// chromeos::AccelerometerReader::Observer, that CanEnterMaximizeMode returns
+// false, and that valid accelerometer events allow entering maximize mode.
+TEST_F(MaximizeModeControllerTest,
+       CanEnterMaximizeModeRequiresValidAccelerometerUpdate) {
+  // Should be false until an accelerometer event is sent.
+  ASSERT_FALSE(maximize_mode_controller()->CanEnterMaximizeMode());
+  OpenLidToAngle(90.0f);
+  EXPECT_TRUE(maximize_mode_controller()->CanEnterMaximizeMode());
+}
+
 class MaximizeModeControllerSwitchesTest : public MaximizeModeControllerTest {
  public:
   MaximizeModeControllerSwitchesTest() {}
   ~MaximizeModeControllerSwitchesTest() override {}
 
   void SetUp() override {
     base::CommandLine::ForCurrentProcess()->AppendSwitch(
         switches::kAshEnableTouchViewTesting);
     MaximizeModeControllerTest::SetUp();
   }
  private:
   DISALLOW_COPY_AND_ASSIGN(MaximizeModeControllerSwitchesTest);
 };
 
 // Tests that when the command line switch for testing maximize mode is on, that
 // accelerometer updates which would normally cause it to exit do not.
 TEST_F(MaximizeModeControllerSwitchesTest, IgnoreHingeAngles) {
   maximize_mode_controller()->EnableMaximizeModeWindowManager(true);
 
   // Would normally trigger an exit from maximize mode.
   OpenLidToAngle(90.0f);
   EXPECT_TRUE(IsMaximizeModeStarted());
 }
 
 }  // namespace ash