Move tools/valgrind-webrtc -> tools-webrtc/valgrind

The WebRTC valgrind wrapper scripts needs to be moved in order to
unlock us from depending on a Chromium checkout.

BUG=webrtc:5006
TBR=ehmaldonado@webrtc.org
NOTRY=True

Review-Url: https://codereview.webrtc.org/2578093002
Cr-Commit-Position: refs/heads/master@{#15662}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index 05297dc..46d1601 100755
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -456,10 +456,10 @@
                   r'^tools[\\\/]refactoring[\\\/].*\.py$',
                   r'^tools[\\\/]swarming_client[\\\/].*\.py$',
                   r'^tools[\\\/]vim[\\\/].*\.py$',
-                  # TODO(phoglund): should arguably be checked.
-                  r'^tools[\\\/]valgrind-webrtc[\\\/].*\.py$',
                   r'^tools[\\\/]valgrind[\\\/].*\.py$',
                   r'^tools[\\\/]win[\\\/].*\.py$',
+                  # TODO(phoglund): should arguably be checked.
+                  r'^tools-webrtc[\\\/]valgrind[\\\/].*\.py$',
                   r'^xcodebuild.*[\\\/].*\.py$',),
       disabled_warnings=['F0401',  # Failed to import x
                          'E0611',  # No package y in x