Media player: Add shortcut keys (Ctrl+Shift+I/J/C/B) to media players for debug.

ui/file_manager/video_player/js/video_player.js

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @param {!HTMLElement} playerContainer Main container.
  * @param {!HTMLElement} videoContainer Container for the video element.
  * @param {!HTMLElement} controlsContainer Container for video controls.
  * @constructor
  * @struct
  * @extends {VideoControls}
  */
 function FullWindowVideoControls(
     playerContainer, videoContainer, controlsContainer) {
   VideoControls.call(this,
       controlsContainer,
       this.onPlaybackError_.wrap(this),
       loadTimeData.getString.wrap(loadTimeData),
       this.toggleFullScreen_.wrap(this),
       videoContainer);
 
   this.playerContainer_ = playerContainer;
   this.decodeErrorOccured = false;
 
   this.casting = false;
 
   this.updateStyle();
   window.addEventListener('resize', this.updateStyle.wrap(this));
   document.addEventListener('keydown', function(e) {
-    switch (e.keyIdentifier) {
+    switch (util.getKeyModifiers(e) + e.keyIdentifier) {
+      // Handle debug shortcut keys.
+      case 'Ctrl-Shift-U+0049': // Ctrl+Shift+I
+        chrome.fileManagerPrivate.openInspector('normal');
+        break;
+      case 'Ctrl-Shift-U+004A': // Ctrl+Shift+J
+        chrome.fileManagerPrivate.openInspector('console');
+        break;
+      case 'Ctrl-Shift-U+0043': // Ctrl+Shift+C
+        chrome.fileManagerPrivate.openInspector('element');
+        break;
+      case 'Ctrl-Shift-U+0042': // Ctrl+Shift+B
+        chrome.fileManagerPrivate.openInspector('background');
+        break;
+
       case 'U+0020': // Space
       case 'MediaPlayPause':
         this.togglePlayStateWithFeedback();
         break;
       case 'U+001B': // Escape
         util.toggleFullScreen(
             chrome.app.window.current(),
             false);  // Leave the full screen mode.
         break;
       case 'Right':
@@ skipping 643 matching lines @@
   return new Promise(function(fulfill, reject) {
     util.URLsToEntries(window.appState.items, function(entries) {
       metrics.recordOpenVideoPlayerAction();
       metrics.recordNumberOfOpenedFiles(entries.length);
 
       player.prepare(entries);
       player.playFirstVideo(player, fulfill);
     }.wrap());
   }.wrap());
 }.wrap());