Orphan headers should check only added files

This CL makes the presubmit check less strict. We can modify untracked
headers but we cannot added them anymore.

In the meatime I am spawning a lot of bugs to fix the currently
untracked headers.

BUG=webrtc:7514
NOTRY=True
TBR=kjellander@webrtc.org

Review-Url: https://codereview.webrtc.org/2873223004
Cr-Commit-Position: refs/heads/master@{#18080}
diff --git a/PRESUBMIT.py b/PRESUBMIT.py
index e13c9a0..e2d0dd5 100755
--- a/PRESUBMIT.py
+++ b/PRESUBMIT.py
@@ -623,7 +623,7 @@
     sys.path = original_sys_path
 
   for f in input_api.AffectedSourceFiles(input_api.FilterSourceFile):
-    if f.LocalPath().endswith('.h'):
+    if f.LocalPath().endswith('.h') and f.Action() == 'A':
       file_path = os.path.abspath(f.LocalPath())
       root_dir = os.getcwd()
       gn_file_path = GetBuildGnPathFromFilePath(file_path, os.path.exists,