Fix code around display overscan settings.

ash/display/multi_display_manager.cc

Index: ash/display/multi_display_manager.cc
diff --git a/ash/display/multi_display_manager.cc b/ash/display/multi_display_manager.cc
index aba85f02e5af38321ebd2485eeec50d0a70b6d03..9bda2d721808e61be3b5fa52c1181ebd3307d762 100644
--- a/ash/display/multi_display_manager.cc
+++ b/ash/display/multi_display_manager.cc
@@ -148,6 +148,18 @@ const gfx::Display& MultiDisplayManager::FindDisplayContainingPoint(
 
 void MultiDisplayManager::SetOverscanInsets(int64 display_id,
                                             const gfx::Insets& insets_in_dip) {
+  std::map<int64, gfx::Insets>::const_iterator old_overscan =
+      overscan_mapping_.find(display_id);
+  if (old_overscan != overscan_mapping_.end()) {
+    gfx::Insets old_insets = old_overscan->second;
+    gfx::Display& display = FindDisplayForId(display_id);
+    if (display.id() != gfx::Display::kInvalidDisplayID) {

[oshima, 2012/10/17 16:34:09]

Can you add Display::is_valid() and use here?

[Jun Mukai, 2012/10/17 16:53:40]

Done.

+      // Reimburse the existing insets before applying the new insets.
+      gfx::Rect bounds = display.bounds_in_pixel();
+      bounds.Inset(old_insets.Scale(-display.device_scale_factor()));
+      display.SetScaleAndBounds(display.device_scale_factor(), bounds);
+    }
+  }
   overscan_mapping_[display_id] = insets_in_dip;
   OnNativeDisplaysChanged(displays_);
 }
@@ -446,7 +458,7 @@ gfx::Display& MultiDisplayManager::FindDisplayForId(int64 id) {
     if ((*iter).id() == id)
       return *iter;
   }
-  DLOG(FATAL) << "Could not find display:" << id;
+  DLOG(WARNING) << "Could not find display:" << id;
   return GetInvalidDisplay();
 }