Copy Crashpad into the Chrome tree instead of importing it via DEPS

third_party/crashpad/README.chromium

 Name: Crashpad
 Short Name: crashpad
-URL: https://crashpad.googlecode.com/
+URL: https://crashpad.chromium.org/
 Version: unknown
-Revision: see DEPS
+Revision: 6bebb10829332dee5c7315abafb0a8bf32840c15
 License: Apache 2.0
 License File: crashpad/LICENSE
 Security Critical: yes
 
 Description:
 Crashpad is a crash-reporting system. It's the successor to Breakpad.
 
+Crashpad’s authoritative upstream repository is
+https://chromium.googlesource.com/crashpad/crashpad.
+
+Because Crashpad depends on some Chromium code (notably base and build), it is
+acceptable to make changes to this in-Chromium copy of Crashpad in order to
+conform to interface changes in Chromium. These changes must be noted in the
+“local modifications” section below, and should also be reflected in the
+authoritative Crashpad repository as soon as practical.
+
+Substantive development must occur in the authoritative Crashpad repository. If
+this type of work is done in the in-Chromium copy, it will be obliterated the
+next time Crashpad is imported into Chromium.
+
+To update the in-Chromium copy of Crashpad, run update.py in this directory.
+
+To carry changes made in Chromium to Crashpad, run:

[Mark Mentovai, 2015/12/09 22:36:57]

I don’t know if we really need to explain this here, it seems kind of out of
scope.

[Robert Sesek, 2015/12/09 22:42:45]

It should be documented somewhere, but yes, maybe here isn't the best place.

+$ cd "${THIS_DIRECTORY}"
+$ mkdir /tmp/patchdir
+$ git format-patch -1 --binary --output-directory=/tmp/patchdir/cur "${HASH}" \
+      --add-header="Message-Id: Merged from chromium ${HASH}" -- crashpad/
+$ cd "${CRASHPAD_DIR}"
+$ git am --3way --message-id -p4 /tmp/patchdir
+
 Local Modifications:
-None.
+ - Cherry-pick upstream 7efdc94f5982a1f9654c53fd4bf5663e5efa66ce.