Add IsInternal property to gfx::Display

ash/display/display_manager_unittest.cc

Index: ash/display/display_manager_unittest.cc
diff --git a/ash/display/display_manager_unittest.cc b/ash/display/display_manager_unittest.cc
index 43e25938f503c3f0c4cb99518df139190c148f5c..2ea2e8ba2db98c3722e27cf1acf78589d164efd9 100644
--- a/ash/display/display_manager_unittest.cc
+++ b/ash/display/display_manager_unittest.cc
@@ -390,6 +390,8 @@ TEST_F(DisplayManagerTest, TestNativeDisplaysChanged) {
   displays.push_back(gfx::Display(11, gfx::Rect(1, 1, 100, 100)));
   display_manager()->OnNativeDisplaysChanged(displays);
   EXPECT_EQ(2U, display_manager()->GetNumDisplays());
+
+  display_manager()->ResetInternalDisplayForTest();
 }
 
 #if defined(OS_WIN)
@@ -522,6 +524,8 @@ TEST_F(DisplayManagerTest, NativeDisplaysChangedAfterPrimaryChange) {
   EXPECT_EQ("-500,0 500x500",
             FindDisplayForId(internal_display_id).bounds().ToString());
   EXPECT_EQ("0,0 100x100", FindDisplayForId(10).bounds().ToString());
+
+  display_manager()->ResetInternalDisplayForTest();
 }
 
 TEST_F(DisplayManagerTest, AutomaticOverscanInsets) {