Revert of 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 7db5ba9108e1d031edde3d1f9025e5af869a769b..3c811d7cf9d116830449d30388135e39a7d47c71 100644
--- a/ash/display/display_manager_unittest.cc
+++ b/ash/display/display_manager_unittest.cc
@@ -98,8 +98,7 @@
   }
 
   // aura::DisplayObserver overrides:
-  virtual void OnDisplayMetricsChanged(const gfx::Display& display,
-                                       uint32_t) OVERRIDE {
+  virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE {
     changed_.push_back(display);
   }
   virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE {
@@ -388,11 +387,8 @@
   EXPECT_EQ(1, host->compositor()->device_scale_factor());
   EXPECT_EQ("1000x600",
             Shell::GetPrimaryRootWindow()->bounds().size().ToString());
-  EXPECT_EQ("1 0 0", GetCountSummary());
-
   UpdateDisplay("1000x600*2");
   EXPECT_EQ(2, host->compositor()->device_scale_factor());
-  EXPECT_EQ("2 0 0", GetCountSummary());
   EXPECT_EQ("500x300",
             Shell::GetPrimaryRootWindow()->bounds().size().ToString());
 }
@@ -850,23 +846,17 @@
   EXPECT_EQ("2 0 0", GetCountSummary());
   reset();
 
-  // Updating to the same configuration should report no changes.
+  // Updating tothe same configuration should report no changes.
   UpdateDisplay("100x200/l,300x400");
   EXPECT_EQ("0 0 0", GetCountSummary());
   reset();
 
-  // Rotating 180 degrees should report one change.
-  UpdateDisplay("100x200/r,300x400");
-  EXPECT_EQ("1 0 0", GetCountSummary());
+  UpdateDisplay("100x200/l,300x400");
+  EXPECT_EQ("0 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");
@@ -1057,7 +1047,8 @@
   virtual ~TestDisplayObserver() {}
 
   // gfx::DisplayObserver overrides:
-  virtual void OnDisplayMetricsChanged(const gfx::Display&,uint32_t) OVERRIDE {}
+  virtual void OnDisplayBoundsChanged(const gfx::Display& display) OVERRIDE {
+  }
   virtual void OnDisplayAdded(const gfx::Display& new_display) OVERRIDE {
     // Mirror window should already be delete before restoring
     // the external display.