Add OnDisplayMetricsChanged in DisplayObserver.

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 3c811d7cf9d116830449d30388135e39a7d47c71..729d1377f92e3207784ab9eaab848d927ebf7e2a 100644
--- a/ash/display/display_manager_unittest.cc
+++ b/ash/display/display_manager_unittest.cc
@@ -98,7 +98,8 @@ class DisplayManagerTest : public test::AshTestBase,
   }
 
   // aura::DisplayObserver overrides:
-  virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE {
+  virtual void OnDisplayMetricsChanged(const gfx::Display& display,
+      DisplayObserver::MetricsType) OVERRIDE {
     changed_.push_back(display);
   }
   virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE {
@@ -846,19 +847,25 @@ TEST_F(DisplayManagerTest, Rotate) {
   EXPECT_EQ("2 0 0", GetCountSummary());
   reset();
 
-  // Updating tothe same configuration should report no changes.
+  // Updating to the same configuration should report no changes.
   UpdateDisplay("100x200/l,300x400");
   EXPECT_EQ("0 0 0", GetCountSummary());
   reset();
 
-  UpdateDisplay("100x200/l,300x400");
-  EXPECT_EQ("0 0 0", GetCountSummary());
+  // Rotating 180 degrees should report one change.
+  UpdateDisplay("100x200/r,300x400");
+  EXPECT_EQ("1 0 0", GetCountSummary());
   reset();
 
   UpdateDisplay("200x200");
   EXPECT_EQ("1 0 1", GetCountSummary());
   reset();
 
+  // Rotating 180 degrees should report one change.
+  UpdateDisplay("200x200/u");
+  EXPECT_EQ("1 0 0", GetCountSummary());
+  reset();
+
   UpdateDisplay("200x200/l");
   EXPECT_EQ("1 0 0", GetCountSummary());
 }
@@ -1047,7 +1054,8 @@ class TestDisplayObserver : public gfx::DisplayObserver {
   virtual ~TestDisplayObserver() {}
 
   // gfx::DisplayObserver overrides:
-  virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE {
+  virtual void OnDisplayMetricsChanged(
+      const gfx::Display&, DisplayObserver::MetricsType) OVERRIDE {
   }
   virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE {
     // Mirror window should already be delete before restoring