Revert "gclient: remove support for $matching_files in hooks"

This reverts commit 3e6d7c1c.

Reason for revert: maybe caused outage.

Original change's description:
> gclient: remove support for $matching_files in hooks
> 
> This feature seems to be unused, and removing it will
> simplify handling hooks a little bit.
> 
> Bug: 661382
> Change-Id: I89f28dedb7f59cd475b176cfb1f023094520d6b7
> Reviewed-on: https://chromium-review.googlesource.com/509614
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Commit-Queue: Paweł Hajdan Jr. <phajdan.jr@chromium.org>
> 

TBR=phajdan.jr@chromium.org,dpranke@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
Bug: 661382

Change-Id: I47fe26e7381682b5b428a3775bf27a551c57d5e6
Reviewed-on: https://chromium-review.googlesource.com/512344Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>

gclient.py

@@ -724,7 +724,7 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
         hooks_to_run.append(hook)
 
     if self.recursion_limit:
-      self._pre_deps_hooks = [self.GetHookAction(hook) for hook in
+      self._pre_deps_hooks = [self.GetHookAction(hook, []) for hook in
                               local_scope.get('pre_deps_hooks', [])]
 
     self.add_dependencies_and_close(deps_to_add, hooks_to_run)
@@ -879,15 +879,19 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
     self._processed = True
 
   @staticmethod
-  def GetHookAction(hook_dict):
+  def GetHookAction(hook_dict, matching_file_list):
     """Turns a parsed 'hook' dict into an executable command."""
     logging.debug(hook_dict)
+    logging.debug(matching_file_list)
     command = hook_dict['action'][:]
     if command[0] == 'python':
       # If the hook specified "python" as the first item, the action is a
       # Python script.  Run it by starting a new copy of the same
       # interpreter.
       command[0] = sys.executable
+    if '$matching_files' in command:
+      splice_index = command.index('$matching_files')
+      command[splice_index:splice_index + 1] = matching_file_list
     return command
 
   def GetHooks(self, options):
@@ -909,7 +913,7 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
           gclient_scm.GetScmName(self.parsed_url) in ('git', None) or
           os.path.isdir(os.path.join(self.root.root_dir, self.name, '.git'))):
         for hook_dict in self.deps_hooks:
-          result.append(self.GetHookAction(hook_dict))
+          result.append(self.GetHookAction(hook_dict, []))
       else:
         # Run hooks on the basis of whether the files from the gclient operation
         # match each hook's pattern.
@@ -919,7 +923,7 @@ class Dependency(gclient_utils.WorkItem, DependencySettings):
               f for f in self.file_list_and_children if pattern.search(f)
           ]
           if matching_file_list:
-            result.append(self.GetHookAction(hook_dict))
+            result.append(self.GetHookAction(hook_dict, matching_file_list))
     for s in self.dependencies:
       result.extend(s.GetHooks(options))
     return result