Allow to find depot tools not in depot_tools folder.

My use case is to have different versions of depot tools
in folders with different names which contain different
incompatible versions of svn inside them.

BUG= none
TEST= gclient runhooks starts downloading VS 2013 toolchain
      when using depot tools in a folder with a different name.

Review URL: https://codereview.chromium.org/183803010

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254822 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/tools/find_depot_tools.py b/tools/find_depot_tools.py
index 32c4d19e..469a283 100644
--- a/tools/find_depot_tools.py
+++ b/tools/find_depot_tools.py
@@ -12,7 +12,7 @@
 
 
 def IsRealDepotTools(path):
-  return os.path.isfile(os.path.join(path, 'breakpad.py'))
+  return os.path.isfile(os.path.join(path, 'gclient'))
 
 
 def add_depot_tools_to_path():
@@ -23,7 +23,7 @@
       return i
   # Then look if depot_tools is in PATH, common case.
   for i in os.environ['PATH'].split(os.pathsep):
-    if i.rstrip(os.sep).endswith('depot_tools') and IsRealDepotTools(i):
+    if IsRealDepotTools(i):
       sys.path.append(i.rstrip(os.sep))
       return i
   # Rare case, it's not even in PATH, look upward up to root.