Add descriptions with examples to run-blink-* scripts.

third_party/WebKit/Tools/Scripts/run-blink-httpd

 #!/usr/bin/env python
 # Copyright (C) 2010 Google Inc. All rights reserved.
 #
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 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 # notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 # copyright notice, this list of conditions and the following disclaimer
 # in the documentation and/or other materials provided with the
 # distribution.
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 # contributors may be used to endorse or promote products derived from
 # this software without specific prior written permission.
 #
 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 # OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 # SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+"""Runs an Apache HTTP server to manually run layout tests locally.
+
+After running this script, you can locally navigate to URLs where
+the path is relative to LayoutTests/http/tests/. For example, to run
+LayoutTests/http/tests/cachestorage/window-cache-add.html, navigate to:
+    http://127.0.0.1:8000/cachestorage/window/cache-add.html
+
+When using HTTPS, for example:
+    https://127.0.0.1:8443/https/verify-ssl-enabled.php
+you will may a certificate warning, which you need to bypass.
+
+After starting the server, you can also run individual layout tests
+via content_shell, e.g.
+    $ out/Release/content_shell --run-layout-test \
+    http://127.0.0.1:8000/security/cross-frame-access-get.html
+
+Note that some tests will only work if "127.0.0.1" for the host part of the
+URL, rather than "localhost".
+"""
+
 import webkitpy.common.version_check
 
 from webkitpy.layout_tests.servers import cli_wrapper
 from webkitpy.layout_tests.servers import apache_http
 
-cli_wrapper.main(apache_http.ApacheHTTP, additional_dirs={}, number_of_servers=4)
+cli_wrapper.main(apache_http.ApacheHTTP, additional_dirs={}, number_of_servers=4, description=__doc__)