[WPT Export] Fix cwd on run_command calls in ChromiumCommit

third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py
index 76e48ec83bd7a21ae46024d2ffe474c07c1d8d9a..efa62248c093e67d83bd8d9ed0aa9ef6949bc941 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/w3c/chromium_commit.py
@@ -31,6 +31,7 @@ class ChromiumCommit(object):
 
             sha = self.position_to_sha(position)
 
+        assert len(sha) == 40, 'Expected SHA-1 hash, got {}'.format(sha)
         self.sha = sha
         self.position = position
 
@@ -40,40 +41,40 @@ class ChromiumCommit(object):
         """
         return len(self.host.executive.run_command([
             'git', 'rev-list', '{}..origin/master'.format(self.sha)
-        ]).splitlines())
+        ], cwd=self.absolute_chromium_dir()).splitlines())
 
     def position_to_sha(self, commit_position):
         return self.host.executive.run_command([
             'git', 'crrev-parse', commit_position
-        ]).strip()
+        ], cwd=self.absolute_chromium_dir()).strip()
 
     def subject(self):
         return self.host.executive.run_command([
             'git', 'show', '--format=%s', '--no-patch', self.sha
-        ])
+        ], cwd=self.absolute_chromium_dir())
 
     def body(self):
         return self.host.executive.run_command([
             'git', 'show', '--format=%b', '--no-patch', self.sha
-        ])
+        ], cwd=self.absolute_chromium_dir())
 
     def author(self):
         return self.host.executive.run_command([
             'git', 'show', '--format="%aN <%aE>"', '--no-patch', self.sha
-        ])
+        ], cwd=self.absolute_chromium_dir())
 
     def message(self):
         """Returns a string with a commit's subject and body."""
         return self.host.executive.run_command([
             'git', 'show', '--format=%B', '--no-patch', self.sha
-        ])
+        ], cwd=self.absolute_chromium_dir())
 
     def filtered_changed_files(self):
         """Makes a patch with just changes in files in the WPT dir for a given commit."""
         changed_files = self.host.executive.run_command([
             'git', 'diff-tree', '--name-only', '--no-commit-id', '-r', self.sha,
             '--', self.absolute_chromium_wpt_dir()
-        ]).splitlines()
+        ], cwd=self.absolute_chromium_dir()).splitlines()
 
         blacklist = [
             'MANIFEST.json',