cros: Allow pin keyboard to keep focus without popping up the pin keyboard.

chrome/browser/resources/chromeos/quick_unlock/pin_keyboard.html

 <!-- TODO(crbug.com/603217): Use i18n instead of string literals. Figure out
                              what i18n to use for keypad, ie, does 1 ABC make
                              sense in every scenario? -->
 
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/i18n_behavior.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-button/paper-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-styles/color.html">
@@ skipping 147 matching lines @@
         margin: 0;
       }
 
       /* Ensure that all children of paper-button do not consume events. This
        * simplifies the event handler code. */
       paper-button * {
         pointer-events: none;
       }
     </style>
 
-    <div id="root" on-keypress="onKeyPress_" on-keydown="onKeyDown_">
+    <div id="root">
       <div id="container-constrained-width">
         <div class="row first-row">
-          <input id="pin-input" type="[[getInputType_(enablePassword)]]"
+          <input id="pin-input" type="password"
                  is-input-rtl$="[[isInputRtl_(value)]]"
                  has-content$="[[hasInput_(value)]]"
                  placeholder="[[getInputPlaceholder_(enablePassword)]]"
-                 value="{{value::input}}"
-                 on-keydown="onInputKeyDown_"
-                 hidden=[[hideInput]]>
+                 on-keydown="onInputKeyDown_">
           </input>
         </div>
         <hr>
         <div class="row keyboard">
           <paper-button class="digit-button" on-tap="onNumberTap_" value="1"
                         noink>
             <inner-text>$i18n{pinKeyboard1}</inner-text>
             <paper-ripple>
           </paper-button>
           <paper-button class="digit-button" on-tap="onNumberTap_" value="2"
@@ skipping 59 matching lines @@
                                noink>
             </paper-icon-button>
             <paper-ripple>
           </div>
         </div>
       </div>
     </div>
   </template>
   <script src="pin_keyboard.js"></script>
 </dom-module>