Fix some typos in GN documentation.

tools/gn/function_template.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "tools/gn/functions.h"
 
 #include "tools/gn/parse_tree.h"
 #include "tools/gn/scope.h"
 #include "tools/gn/template.h"
 #include "tools/gn/value.h"
@@ skipping 54 matching lines @@
     "    idl(\"foo\") {...\n"
     "  you will normally want this to expand to something defining a\n"
     "  source_set or static_library named \"foo\" (among other things you may\n"
     "  need). This way, when another target specifies a dependency on\n"
     "  \"foo\", the static_library or source_set will be linked.\n"
     "\n"
     "  It is also important that any other targets your template expands to\n"
     "  have globally unique names, or you will get collisions.\n"
     "\n"
     "  Access the invoking name in your template via the implicit\n"
-    "  \"target_name\" variable. This should also be the basis of how other\n"
-    "  targets that a template expands to to ensure uniquness.\n"
+    "  \"target_name\" variable. This should also be the basis for how other\n"
+    "  targets that a template expands to ensure uniqueness.\n"
     "\n"
     "  A typical example would be a template that defines an action to\n"
     "  generate some source files, and a source_set to compile that source.\n"
     "  Your template would name the source_set \"target_name\" because\n"
     "  that's what you want external targets to depend on to link your code.\n"
     "  And you would name the action something like \"${target_name}_action\"\n"
     "  to make it unique. The source set would have a dependency on the\n"
     "  action to make it run.\n"
     "\n"
     "Example of defining a template:\n"
@@ skipping 102 matching lines @@
     err->AppendSubErr(Err(existing_template->GetDefinitionRange(),
                           "Previous definition."));
     return Value();
   }
 
   scope->AddTemplate(template_name, new Template(scope, function));
   return Value();
 }
 
 }  // namespace functions