toolchain-utils: fix results_cache_unittest.py

The test was failing with "RuntimeError: Could not run find command!".
It broke after https://chrome-internal-review.googlesource.com/#/c/270698
which added GetResultsFile(). This CL adds the Fake version for testing.

BUG=None
TEST='./results_cache_unittest.py passes'

Change-Id: I2bb92a394c8756bfb30941ce12e87396b22efe02
Reviewed-on: https://chrome-internal-review.googlesource.com/272168
Commit-Ready: Rahul Chaudhry <rahulchaudhry@google.com>
Tested-by: Rahul Chaudhry <rahulchaudhry@google.com>
Reviewed-by: Caroline Tice <cmtice@google.com>
diff --git a/crosperf/results_cache_unittest.py b/crosperf/results_cache_unittest.py
index 1003173..85ed8a8 100755
--- a/crosperf/results_cache_unittest.py
+++ b/crosperf/results_cache_unittest.py
@@ -185,6 +185,7 @@
     self.kv_dict = None
     self.tmpdir = ''
     self.callGetNewKeyvals = False
+    self.callGetResultsFile = False
     self.callGetPerfDataFiles = False
     self.args = None
     self.callGatherPerfResults = False
@@ -544,6 +545,10 @@
       self.callGetResultsDir = True
       return '/tmp/results_dir'
 
+    def FakeGetResultsFile():
+      self.callGetResultsFile = True
+      return []
+
     def FakeGetPerfDataFiles():
       self.callGetPerfDataFiles = True
       return []
@@ -563,11 +568,13 @@
     self.result.chromeos_root = '/tmp/chromeos'
 
     self.callGetResultsDir = False
+    self.callGetResultsFile = False
     self.callGetPerfDataFiles = False
     self.callGetPerfReportFiles = False
     self.callProcessResults = False
 
     self.result.GetResultsDir = FakeGetResultsDir
+    self.result.GetResultsFile = FakeGetResultsFile
     self.result.GetPerfDataFiles = FakeGetPerfDataFiles
     self.result.GeneratePerfReportFiles = FakeGetPerfReportFiles
     self.result.ProcessResults = FakeProcessResults
@@ -575,6 +582,7 @@
     self.result.PopulateFromRun(OUTPUT, '', 0, 'test',
                                 'telemetry_Crosperf')
     self.assertTrue(self.callGetResultsDir)
+    self.assertTrue(self.callGetResultsFile)
     self.assertTrue(self.callGetPerfDataFiles)
     self.assertTrue(self.callGetPerfReportFiles)
     self.assertTrue(self.callProcessResults)