[telemetry] Support absolute paths by changing file:/// to file://. More robust file path handling.

tools/telemetry/telemetry/page/page_set.py

Index: tools/telemetry/telemetry/page/page_set.py
diff --git a/tools/telemetry/telemetry/page/page_set.py b/tools/telemetry/telemetry/page/page_set.py
index a01b80a73b61e463af5c5b7b3b12075d03b8729a..6a0e165e511ea42e0105fe3a01c5d9dc933093ec 100644
--- a/tools/telemetry/telemetry/page/page_set.py
+++ b/tools/telemetry/telemetry/page/page_set.py
@@ -1,6 +1,7 @@
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
+
 import csv
 import json
 import os
@@ -9,11 +10,14 @@ from telemetry.page import cloud_storage
 from telemetry.page import page as page_module
 from telemetry.page import page_set_archive_info
 
+
 class PageSet(object):
   def __init__(self, file_path='', attributes=None):
+    self.file_path = file_path
+
+    # These attributes can be set dynamically by the page set.
     self.description = ''
     self.archive_data_file = ''
-    self.file_path = file_path
     self.credentials_path = None
     self.user_agent_type = None
     self.make_javascript_deterministic = True
@@ -40,24 +44,33 @@ class PageSet(object):
             url, self, attributes=page_attributes, base_dir=self._base_dir)
         self.pages.append(page)
 
+    # Prepend _base_dir to our serving dirs.
+    # Always use realpath to ensure no duplicates in set.
+    self.serving_dirs = set()
+    if attributes and 'serving_dirs' in attributes:
+      if not isinstance(attributes['serving_dirs'], list):
+        raise ValueError('serving_dirs must be a list.')
+      for serving_dir in attributes['serving_dirs']:
+        self.serving_dirs.add(
+            os.path.realpath(os.path.join(self._base_dir, serving_dir)))
+
     # Attempt to download the credentials file.
     if self.credentials_path:
       cloud_storage.GetIfChanged(
           cloud_storage.INTERNAL_BUCKET,
           os.path.join(self._base_dir, self.credentials_path))
 
-    # For every file:// URL, scan that directory for .sha1 files,
+    # Scan every serving directory for .sha1 files
     # and download them from Cloud Storage. Assume all data is public.
-    all_serving_dirs = set()
+    all_serving_dirs = self.serving_dirs.copy()
+    # Add individual page dirs to all serving dirs.
     for page in self:
       if page.is_file:
-        serving_dirs, _ = page.serving_dirs_and_file
-        if isinstance(serving_dirs, list):
-          all_serving_dirs |= set(serving_dirs)
-        else:
-          all_serving_dirs.add(serving_dirs)
-
+        all_serving_dirs.add(page.serving_dir)
+    # Scan all serving dirs.
     for serving_dir in all_serving_dirs:
+      if serving_dir == '/':
+        raise ValueError('Trying to serve "/" from HTTP server.')
       for dirpath, _, filenames in os.walk(serving_dir):
         for filename in filenames:
           path, extension = os.path.splitext(