Use Git hash to post try job http request to bisect builders.

Always use Git hash to post build request since Commit positions are
not supported by builders to build.

BUG=407898
NOTRY=true

Review URL: https://codereview.chromium.org/508723004

Cr-Commit-Position: refs/heads/master@{#292188}

tools/bisect-perf-regression.py

@@ -1307,7 +1307,7 @@ class BisectPerformanceMetrics(object):
         os.remove(downloaded_file)
     return False
 
-  def PostBuildRequestAndWait(self, revision, fetch_build, patch=None):
+  def PostBuildRequestAndWait(self, git_revision, fetch_build, patch=None):
     """POSTs the build request job to the try server instance.
 
     A try job build request is posted to tryserver.chromium.perf master,
@@ -1316,7 +1316,7 @@ class BisectPerformanceMetrics(object):
     into the output folder.
 
     Args:
-      revision: A Git hash revision.
+      git_revision: A Git hash revision.
       fetch_build: Function to check and download build from cloud storage.
       patch: A DEPS patch (used while bisecting 3rd party repositories).
 
@@ -1324,12 +1324,6 @@ class BisectPerformanceMetrics(object):
       Downloaded archive file path when requested build exists and download is
       successful, otherwise None.
     """
-    # Get SVN revision for the given SHA.
-    svn_revision = self.source_control.SVNFindRev(revision)
-    if not svn_revision:
-      raise RuntimeError(
-          'Failed to determine SVN revision for %s' % revision)
-
     def GetBuilderNameAndBuildTime(target_platform, target_arch='ia32'):
       """Gets builder bot name and build time in seconds based on platform."""
       # Bot names should match the one listed in tryserver.chromium's
@@ -1355,11 +1349,13 @@ class BisectPerformanceMetrics(object):
     # Create a unique ID for each build request posted to try server builders.
     # This ID is added to "Reason" property of the build.
     build_request_id = GetSHA1HexDigest(
-        '%s-%s-%s' % (svn_revision, patch, time.time()))
+        '%s-%s-%s' % (git_revision, patch, time.time()))
 
     # Creates a try job description.
+    # Always use Git hash to post build request since Commit positions are
+    # not supported by builders to build.
     job_args = {
-        'revision': 'src@%s' % svn_revision,
+        'revision': 'src@%s' % git_revision,
         'bot': bot_name,
         'name': build_request_id,
     }
@@ -1372,10 +1368,10 @@ class BisectPerformanceMetrics(object):
           fetch_build, bot_name, builder_host, builder_port, build_request_id,
           build_timeout)
       if not target_file:
-        print '%s [revision: %s]' % (error_msg, svn_revision)
+        print '%s [revision: %s]' % (error_msg, git_revision)
         return None
       return target_file
-    print 'Failed to post build request for revision: [%s]' % svn_revision
+    print 'Failed to post build request for revision: [%s]' % git_revision
     return None
 
   def IsDownloadable(self, depot):