chromeos: Move "Set Time" webui files into a new subdirectory

I'm going to fork them to create a material design version of this
dialog and I don't want to pollute the main c/b/resources/chromeos
directory.

Bug: 927732
Test: browser_tests SetTimeWebUITest.testChangeTimezone
Change-Id: I5463a76d3da6d7784635ec9126c4ac64186f219d
Reviewed-on: https://chromium-review.googlesource.com/c/1496491
Commit-Queue: James Cook <jamescook@chromium.org>
Auto-Submit: James Cook <jamescook@chromium.org>
Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636916}

chrome/browser/browser_resources.grd

@@ -647,9 +647,9 @@
         <include name="IDR_DEVICE_EMULATOR_SHARED_STYLES_HTML" file="resources\chromeos\emulator\shared_styles.html" type="BINDATA" />
       </if>
       <if expr="chromeos">
-        <include name="IDR_SET_TIME_HTML" file="resources\chromeos\set_time.html" type="BINDATA" />
-        <include name="IDR_SET_TIME_CSS" file="resources\chromeos\set_time.css" type="BINDATA" />
-        <include name="IDR_SET_TIME_JS" file="resources\chromeos\set_time.js" type="BINDATA" />
+        <include name="IDR_SET_TIME_HTML" file="resources\chromeos\set_time\set_time.html" type="BINDATA" />
+        <include name="IDR_SET_TIME_CSS" file="resources\chromeos\set_time\set_time.css" type="BINDATA" />
+        <include name="IDR_SET_TIME_JS" file="resources\chromeos\set_time\set_time.js" type="BINDATA" />
       </if>
       <if expr="chromeos">
         <if expr="_google_chrome">