arc: avoid checkbox AutomationNode issue

chrome/browser/resources/chromeos/arc_support/main.html

Index: chrome/browser/resources/chromeos/arc_support/main.html
diff --git a/chrome/browser/resources/chromeos/arc_support/main.html b/chrome/browser/resources/chromeos/arc_support/main.html
index eb7795c6ace7617b1c3ddecdb8afa7f964748e49..75580af15e83d7ce6793386f916e634a434f99de 100644
--- a/chrome/browser/resources/chromeos/arc_support/main.html
+++ b/chrome/browser/resources/chromeos/arc_support/main.html
@@ -63,23 +63,17 @@
           <webview id="terms-view" partition="persist:arc_support"></webview>
         </div>
         <label class="layout horizontal section-checkbox-container">
-          <div class="checkbox-container" id="enable-metrics-container" hidden>

[khmel, 2016/08/17 23:24:50]

Div is required here, please see my comment:
https://codereview.chromium.org/2179803002/diff/20001/chrome/browser/resource...

I found weird behavior when size of checkbox depends on number of lines in text
description. This makes checkbox with declared 16px in css file appeared as 12px
checkbox for 2 lines and 8px for 3 lines text description
(https://drive.google.com/a/google.com/file/d/0B63tZNwdjs-qejg3dEMwek9TLVk/vie...).
It was also not possible to apply padding because it was ignored. I found
workaround by wrapping checkbox by div.

[yawano, 2016/08/17 23:54:06]

Does it happen with myCL? That's the reason I've added flex-shrink to the input
element. I saw it without flex-shrink, but I don't see it with flex-shrink.

IIUC, it happens since the size of input element is adjusted based on the size
of the text. Specifying flex-shrink: 0 should prevent it.

Also I've used margin to the input element in this CL instead of padding.

-            <input type="checkbox" class="checkbox-option" id="enable-metrics">
-          </div>
+          <input type="checkbox" class="checkbox-option" id="enable-metrics">
           <p class="checkbox-text" id="text-metrics"></p>
         </label>
         <label class="layout horizontal section-checkbox-container">
-          <div class="checkbox-container">
-            <input type="checkbox" class="checkbox-option"
-                id="enable-backup-restore">
-          </div>
+          <input type="checkbox" class="checkbox-option"
+              id="enable-backup-restore">
           <p class="checkbox-text" id="text-backup-restore"></p>
         </label>
         <label class="layout horizontal section-checkbox-container">
-          <div class="checkbox-container">
-            <input type="checkbox" class="checkbox-option"
-                id="enable-location-service">
-          </div>
+          <input type="checkbox" class="checkbox-option"
+              id="enable-location-service">
           <p class="checkbox-text" id="text-location-service"></p>
         </label>
         <div class="layout horizontal end-justified section-buttons">