Added test files for SystemInfo.m and OmahaXMLRequest.m.

chrome/installer/mac/app/testing/requestCheck.dtd

Index: chrome/installer/mac/app/testing/requestCheck.dtd
diff --git a/chrome/installer/mac/app/testing/requestCheck.dtd b/chrome/installer/mac/app/testing/requestCheck.dtd
new file mode 100644
index 0000000000000000000000000000000000000000..5eff1daa5322d7aebfc88376ff68534040fb6fcb
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+++ b/chrome/installer/mac/app/testing/requestCheck.dtd
@@ -0,0 +1,65 @@
+<!--
+
+  Welcome to a document type declaration (DTD).
+  This is a document that makes sure XML files are correctly formed.
+
+  Below, |request| is implied to be the root element of the XML document, whose
+  children are |os| and |app|.
+-->
+<!ELEMENT request (os, app)>
+<!--
+
+  Below, this indicates that |protocol| is a required attribute of the

[Elly Fong-Jones, 2016/07/22 17:39:08]

Nice documentation :D

+  |request| element; by indicating `NMTOKEN`, we indicate that this attribute
+  must have a value associated with it that does not contain whitespace. `CDATA`
+  would be the more commonly used keyword for content with whitespace.
+-->
+<!ATTLIST request protocol NMTOKEN #REQUIRED>
+<!--
+
+  The |os| element should not have any children and cannot have any content
+  within the tag. (<os/> and <os></os> are allowed, but <os>stuff here!</os> is
+  not a valid element.)
+-->
+<!ELEMENT os EMPTY>
+<!--
+
+  This |platform| attribute is a required attribute of |os|, and its value must
+  be "mac".
+-->
+<!ATTLIST os platform (mac) #REQUIRED>
+<!--
+
+  The |version|, |arch|, and |sp| attributes are optional attributes of |os|. If
+  a request's XML body has the |sp|, it may not need the version or arch; if the
+  |sp| is not included but |version| and |arch| are specified, the XML body is
+  still valid. Unfortunately there is relatively less logic available for
+  attributes, so I currently cannot reject the XML document if there is only
+  either |arch| or |version|.
+-->
+<!ATTLIST os version NMTOKEN #IMPLIED>
+<!ATTLIST os arch NMTOKEN #IMPLIED>
+<!ATTLIST os sp NMTOKEN #IMPLIED>
+<!--
+
+  |app| has only one child, |updatecheck|.
+-->
+<!ELEMENT app (updatecheck)>
+<!--
+
+  The |appid| attribute of the |app| element must have "com.google.Chrome" as
+  its value.
+-->
+<!ATTLIST app appid (com.google.Chrome) #REQUIRED>
+<!--
+
+  The following two attributes are required; their values must not contain
+  whitespace.
+-->
+<!ATTLIST app version NMTOKEN #REQUIRED>
+<!ATTLIST app lang NMTOKEN #REQUIRED>
+<!--
+
+  |updatecheck| must be an empty element.
+-->
+<!ELEMENT updatecheck EMPTY>