[Findit] Fix blame for GIT and uptake bug fix.

tools/findit/findit_for_crash.py

Index: tools/findit/findit_for_crash.py
diff --git a/tools/findit/findit_for_crash.py b/tools/findit/findit_for_crash.py
index 50f12d85618577f291298b69faba15029d205123..886e757ef7474dbcdbf28aa4689d3be7ef0937f9 100644
--- a/tools/findit/findit_for_crash.py
+++ b/tools/findit/findit_for_crash.py
@@ -3,7 +3,7 @@
 # found in the LICENSE file.
 
 import os
-from threading import Lock, Thread
+from threading import Lock
 
 import blame
 from common import utils
@@ -139,8 +139,8 @@ def FindMatch(revisions_info_map, file_to_revision_info, file_to_crash_info,
     Matches, a set of match objects.
   """
   matches = match_set.MatchSet(codereview_api_url)
-  threads = []
 
+  tasks = []
   # Iterate through the crashed files in the stacktrace.
   for crashed_file_path in file_to_crash_info:
     # Ignore header file.
@@ -172,17 +172,16 @@ def FindMatch(revisions_info_map, file_to_revision_info, file_to_crash_info,
 
         revision = revisions_info_map[cl]
 
-        match_thread = Thread(
-            target=GenerateMatchEntry,
-            args=[matches, revision, cl, changed_file_path, functions,
+        tasks.append({
+            'function': GenerateMatchEntry,
+            'args': [matches, revision, cl, changed_file_path, functions,
                   component_path, component_name, crashed_line_numbers,
                   stack_frame_nums, file_change_type,
-                  repository_parser])
-        threads.append(match_thread)
-        match_thread.start()
+                  repository_parser]
+        })
 
-  for match_thread in threads:
-    match_thread.join()
+  # Run all the tasks.
+  crash_utils.RunTasks(tasks)
 
   matches.RemoveRevertedCLs()
 
@@ -241,8 +240,8 @@ def FindMatchForCallstack(
                                                             components)
   callstack_priority = callstack.priority
 
+  tasks = []
   # Iterate through all components and create new thread for each component.
-  threads = []
   for component_path in component_dict:
     # If the component to consider in this callstack is not in the parsed list
     # of components, ignore this one.
@@ -251,15 +250,14 @@ def FindMatchForCallstack(
 
     changelog = component_to_changelog_map[component_path]
     file_to_crash_info = component_dict.GetFileDict(component_path)
-    t = Thread(
-        target=FindMatchForComponent,
-        args=[component_path, file_to_crash_info, changelog,
-              callstack_priority, results, results_lock])
-    threads.append(t)
-    t.start()
+    tasks.append({
+        'function': FindMatchForComponent,
+        'args': [component_path, file_to_crash_info, changelog,
+                 callstack_priority, results, results_lock]
+    })
 
-  for t in threads:
-    t.join()
+  # Run all the tasks.
+  crash_utils.RunTasks(tasks)
 
 
 def FindMatchForStacktrace(stacktrace, components,
@@ -320,18 +318,17 @@ def FindMatchForStacktrace(stacktrace, components,
                                                   revisions,
                                                   file_to_revision_map)
 
+  tasks = []
   # Create separate threads for each of the call stack in the stacktrace.
-  threads = []
   for callstack in stacktrace.stack_list:
-    t = Thread(
-        target=FindMatchForCallstack,
-        args=[callstack, components, component_to_changelog_map,
-              results, results_lock])
-    threads.append(t)
-    t.start()
+    tasks.append({
+        'function': FindMatchForCallstack,
+        'args': [callstack, components, component_to_changelog_map,
+                 results, results_lock]
+    })
 
-  for t in threads:
-    t.join()
+  # Run all the tasks.
+  crash_utils.RunTasks(tasks)
 
   return results
 
@@ -477,8 +474,8 @@ def GenerateReasonForMatches(matches):
         pretty_file_names = crash_utils.PrettifyList(file_names)
 
         # Add the reason, break because we took care of the rest of the files.
-        file_string += '(%s)' % crash_utils.PrettifyFrameInfo(
-            stack_frame_indices, function_list)
+        file_string += ('(and is part of stack %s)' %
+            crash_utils.PrettifyFrameInfo(stack_frame_indices, function_list))
         reason.append(file_string % pretty_file_names)
         break
 
@@ -522,8 +519,8 @@ def CombineMatches(matches):
     if match.min_distance_info:
       file_name, min_crashed_line, min_changed_line = match.min_distance_info
       match.reason += \
-          ('Minimum distance from crashed line to changed line: %d. '
-           '(File: %s, Crashed on: %d, Changed: %d).\n' %
+          ('\nMinimum distance from crash line to modified line: %d. '
+           '(file: %s, crashed on: %d, modified: %d).\n' %
            (match.min_distance, file_name, min_crashed_line, min_changed_line))
 
   return combined_matches
@@ -668,8 +665,8 @@ def FindItForCrash(stacktrace_list,
 
   if result:
     return_message = (
-        'No CL in the regression changes the crashed files. The result is '
-        'the blame information.')
+        'No CL in the regression range changes the crashed files. '
+        'The result is the blame information.')
 
   # When findit could not find any CL that changes file in stacktrace or if
   # if cannot get any blame information, return a message saying that no