Make extensions::DictionaryBuilder and extensions::ListValue unmovable.

There's no reason for these classes to be movable. std::move() is just
being used as a synonym for Build().

In addition:
- Build() is fewer characters than std::move().
- clang-format works better when builder syntax is consistently used,
  which makes it easier for readers to visually match up deeply nested
  builders.
- It's surprising to see std::move() used with what looks like a
  temporary.

BUG=none

Review URL: https://codereview.chromium.org/1739183003

Cr-Commit-Position: refs/heads/master@{#378107}
diff --git a/chrome/browser/extensions/test_extension_environment.cc b/chrome/browser/extensions/test_extension_environment.cc
index a85b5d4..37f5628 100644
--- a/chrome/browser/extensions/test_extension_environment.cc
+++ b/chrome/browser/extensions/test_extension_environment.cc
@@ -60,11 +60,14 @@
       .Set("name", "Test App Name")
       .Set("version", "2.0")
       .Set("manifest_version", 2)
-      .Set("app", std::move(extensions::DictionaryBuilder().Set(
-                      "background",
-                      std::move(extensions::DictionaryBuilder().Set(
-                          "scripts", std::move(extensions::ListBuilder().Append(
-                                         "background.js")))))))
+      .Set("app", extensions::DictionaryBuilder()
+                      .Set("background",
+                           extensions::DictionaryBuilder()
+                               .Set("scripts", extensions::ListBuilder()
+                                                   .Append("background.js")
+                                                   .Build())
+                               .Build())
+                      .Build())
       .Build();
 }