Show "displays" section in the options page even for 1 display. It happens in case of mirroring.

BUG=135580
TEST=manually checked on lumpy


Review URL: https://chromiumcodereview.appspot.com/10828005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@149113 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/resources/options2/chromeos/display_options.js

@@ -226,23 +226,31 @@ cr.define('options', function() {
      * @private
      */
     layoutMirroringDisplays_: function() {
+      // Offset pixels for secondary display rectangles.
+      /** @const */ var MIRRORING_OFFSET_PIXELS = 2;
+      // Always show two displays because there must be two displays when
+      // the display_options is enabled.  Don't rely on displays_.length because
+      // there is only one display from chrome's perspective in mirror mode.
+      /** @const */ var MIN_NUM_DISPLAYS = 2;
+
       // The width/height should be same as the primary display:
       var width = this.displays_[0].width * VISUAL_SCALE;
       var height = this.displays_[0].height * VISUAL_SCALE;
 
+      var num_displays = Math.max(MIN_NUM_DISPLAYS, this.displays_.length);
+
       this.displays_view_.style.height =
-        height + this.displays_.length * 2 + 'px';
+        height + num_displays * MIRRORING_OFFSET_PIXELS + 'px';
 
-      for (var i = 0; i < this.displays_.length; i++) {
+      for (var i = 0; i < num_displays; i++) {
         var div = document.createElement('div');
-        this.displays_[i].div = div;
         div.className = 'displays-display';
-        div.style.top = i * 2 + 'px';
-        div.style.left = i * 2 + 'px';
+        div.style.top = i * MIRRORING_OFFSET_PIXELS + 'px';
+        div.style.left = i * MIRRORING_OFFSET_PIXELS + 'px';
         div.style.width = width + 'px';
         div.style.height = height + 'px';
         div.style.zIndex = i;
-        if (i == this.displays_.length - 1)
+        if (i == num_displays - 1)
           div.className += ' displays-primary';
         this.displays_view_.appendChild(div);
       }
@@ -330,9 +338,6 @@ cr.define('options', function() {
 
       this.displays_ = displays;
 
-      if (this.displays_.length <= 1)
-        return;
-
       this.resetDisplaysView_();
       if (this.mirroring_)
         this.layoutMirroringDisplays_();

chrome/browser/ui/webui/options2/chromeos/display_options_handler.cc

@@ -84,13 +84,10 @@ void DisplayOptionsHandler::OnDisplayRemoved(const gfx::Display& old_display) {
 }
 
 void DisplayOptionsHandler::UpdateDisplaySectionVisibility() {
-  aura::DisplayManager* display_manager =
-      aura::Env::GetInstance()->display_manager();
   chromeos::OutputState output_state =
       ash::Shell::GetInstance()->output_configurator()->output_state();
   base::FundamentalValue show_options(
       DisplayController::IsExtendedDesktopEnabled() &&
-      display_manager->GetNumDisplays() > 1 &&
       output_state != chromeos::STATE_INVALID &&
       output_state != chromeos::STATE_HEADLESS &&
       output_state != chromeos::STATE_SINGLE);