[Telemetry] Fix finding of minidump_stackwalk binary on mac.

The mac binary is in a subdirectory of the build directory, so it doesn't
work to simply take the dirname of the chrome executable. Instead, factor
out a FindSupportBinary() method that knows about the build directories.

We should use this for finding any other binaries like forwarder, md5sum, etc.

BUG=223572

Review URL: https://chromiumcodereview.appspot.com/23064005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@217962 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 24 insertions, 23 deletions

diff --git a/tools/telemetry/telemetry/core/chrome/desktop_browser_backend.py b/tools/telemetry/telemetry/core/chrome/desktop_browser_backend.py
index 61644c1..7a154b9 100644
--- a/tools/telemetry/telemetry/core/chrome/desktop_browser_backend.py
+++ b/tools/telemetry/telemetry/core/chrome/desktop_browser_backend.py
@@ -149,9 +149,8 @@ class DesktopBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
       return ''
 
   def GetStackTrace(self):
-    executable_dir = os.path.dirname(self._executable)
-    stackwalk = os.path.join(executable_dir, 'minidump_stackwalk')
-    if not os.path.exists(stackwalk):
+    stackwalk = util.FindSupportBinary('minidump_stackwalk')
+    if not stackwalk:
       logging.warning('minidump_stackwalk binary not found. Must build it to '
                       'symbolize crash dumps. Returning browser stdout.')
       return self.GetStandardOutput()
@@ -169,17 +168,18 @@ class DesktopBrowserBackend(chrome_browser_backend.ChromeBrowserBackend):
       with open(minidump, 'wb') as outfile:
         outfile.write(''.join(infile.read().partition('MDMP')[1:]))
 
-    symbols = glob.glob(os.path.join(executable_dir, 'chrome.breakpad.*'))[0]
+    symbols = glob.glob(os.path.join(os.path.dirname(stackwalk),
+                                     'chrome.breakpad.*'))
     if not symbols:
       logging.warning('No breakpad symbols found. Returning browser stdout.')
       return self.GetStandardOutput()
 
     symbols_path = os.path.join(self._tmp_minidump_dir, 'symbols')
-    with open(symbols, 'r') as f:
+    with open(symbols[0], 'r') as f:
       _, _, _, sha, binary = f.readline().split()
     symbol_path = os.path.join(symbols_path, binary, sha)
     os.makedirs(symbol_path)
-    shutil.copyfile(symbols, os.path.join(symbol_path, binary + '.sym'))
+    shutil.copyfile(symbols[0], os.path.join(symbol_path, binary + '.sym'))
 
     error = tempfile.NamedTemporaryFile('w', 0)
     return subprocess.Popen(
diff --git a/tools/telemetry/telemetry/core/platform/desktop_platform_backend.py b/tools/telemetry/telemetry/core/platform/desktop_platform_backend.py
index b71deab..e2bceaa 100644
--- a/tools/telemetry/telemetry/core/platform/desktop_platform_backend.py
+++ b/tools/telemetry/telemetry/core/platform/desktop_platform_backend.py
@@ -17,26 +17,10 @@ class DesktopPlatformBackend(platform_backend.PlatformBackend):
   def GetFlushUtilityName(self):
     return NotImplementedError()
 
-  def _FindNewestFlushUtility(self):
-    flush_command = None
-    flush_command_mtime = 0
-
-    chrome_root = util.GetChromiumSrcDir()
-    for build_dir, build_type in util.GetBuildDirectories():
-      candidate = os.path.join(chrome_root, build_dir, build_type,
-                               self.GetFlushUtilityName())
-      if os.access(candidate, os.X_OK):
-        candidate_mtime = os.stat(candidate).st_mtime
-        if candidate_mtime > flush_command_mtime:
-          flush_command = candidate
-          flush_command_mtime = candidate_mtime
-
-    return flush_command
-
   def FlushSystemCacheForDirectory(self, directory, ignoring=None):
     assert directory and os.path.exists(directory), \
         'Target directory %s must exist' % directory
-    flush_command = self._FindNewestFlushUtility()
+    flush_command = util.FindSupportBinary(self.GetFlushUtilityName())
     assert flush_command, \
         'You must build %s first' % self.GetFlushUtilityName()
 
diff --git a/tools/telemetry/telemetry/core/util.py b/tools/telemetry/telemetry/core/util.py
index 3e60e75..fe20924 100644
--- a/tools/telemetry/telemetry/core/util.py
+++ b/tools/telemetry/telemetry/core/util.py
@@ -124,3 +124,20 @@ def GetBuildDirectories():
   for build_dir in build_dirs:
     for build_type in build_types:
       yield build_dir, build_type
+
+def FindSupportBinary(binary_name):
+  """Returns the path to the given binary name."""
+  # TODO(tonyg/dtu): This should support finding binaries in cloud storage.
+  command = None
+  command_mtime = 0
+
+  chrome_root = GetChromiumSrcDir()
+  for build_dir, build_type in GetBuildDirectories():
+    candidate = os.path.join(chrome_root, build_dir, build_type, binary_name)
+    if os.path.isfile(candidate) and os.access(candidate, os.X_OK):
+      candidate_mtime = os.stat(candidate).st_mtime
+      if candidate_mtime > command_mtime:
+        command = candidate
+        command_mtime = candidate_mtime
+
+  return command