Add a "pub dependencies" command.

sdk/lib/_internal/pub/test/pub_test.dart

Index: sdk/lib/_internal/pub/test/pub_test.dart
diff --git a/sdk/lib/_internal/pub/test/pub_test.dart b/sdk/lib/_internal/pub/test/pub_test.dart
index 34b3a049b079e5e4b515c5b87c76e34d3ff6fe43..8c6227eb464f6392d4798948243aeb232723e60d 100644
--- a/sdk/lib/_internal/pub/test/pub_test.dart
+++ b/sdk/lib/_internal/pub/test/pub_test.dart
@@ -30,6 +30,7 @@ final USAGE_STRING = """
     Available commands:
       build      Apply transformers to build a package.
       cache      Work with the system cache.
+      deps       Print package dependencies.
       get        Get the current package's dependencies.
       help       Display help information for Pub.
       publish    Publish the current package to pub.dartlang.org.
@@ -87,10 +88,10 @@ main() {
     schedulePub(args: ['cache', '--help'],
         output: '''
           Work with the system cache.
-          
+
           Usage: pub cache <subcommand>
           -h, --help    Print usage information for this command.
-          
+
           Available subcommands:
             add   Install a package.
      ''');
@@ -105,10 +106,11 @@ main() {
     schedulePub(args: ['quylthulg'],
         error: '''
         Could not find a command named "quylthulg".
-   
+
         Available commands:
           build      Apply transformers to build a package.
           cache      Work with the system cache.
+          deps       Print package dependencies.
           get        Get the current package's dependencies.
           help       Display help information for Pub.
           publish    Publish the current package to pub.dartlang.org.
@@ -124,7 +126,7 @@ main() {
     schedulePub(args: ['cache', 'quylthulg'],
         error: '''
         Could not find a subcommand named "quylthulg" for "pub cache".
-   
+
         Usage: pub cache <subcommand>
         -h, --help    Print usage information for this command.
 
@@ -214,7 +216,7 @@ main() {
           output: '''
             Run a local web development server.
 
-            By default, this serves "web/" and "test/", but an explicit list of 
+            By default, this serves "web/" and "test/", but an explicit list of
             directories to serve can be provided as well.
 
             Usage: pub serve [directories...]
@@ -252,6 +254,7 @@ main() {
             Available commands:
               build      Apply transformers to build a package.
               cache      Work with the system cache.
+              deps       Print package dependencies.
               get        Get the current package's dependencies.
               help       Display help information for Pub.
               publish    Publish the current package to pub.dartlang.org.
@@ -270,7 +273,7 @@ main() {
 
             Usage: pub cache <subcommand>
             -h, --help    Print usage information for this command.
-    
+
             Available subcommands:
               add   Install a package.
             ''',