Revert of [Telemetry][CodeHealth] Make unittests with fake platforms use fakes.FakePlatform

telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent_unittest.py

Index: telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent_unittest.py
diff --git a/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent_unittest.py b/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent_unittest.py
index 440d9036fc6a27b628cdf0b21db4deea0c0a7b54..1c6dc065f95f5fa39b3deff074b1e8f355747d99 100644
--- a/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent_unittest.py
+++ b/telemetry/telemetry/internal/platform/tracing_agent/battor_tracing_agent_unittest.py
@@ -8,7 +8,6 @@
 from battor import battor_wrapper
 from devil.android import battery_utils
 from telemetry.internal.platform.tracing_agent import battor_tracing_agent
-from telemetry.testing import fakes
 from telemetry.timeline import trace_data
 from telemetry.timeline import tracing_config
 from tracing.trace_data import trace_data
@@ -27,6 +26,28 @@
 
   def GetCharging(self):
     return self._charging_state
+
+
+class FakePlatformBackend(object):
+  def GetOSName(self):
+    return ''
+
+
+class FakeAndroidPlatformBackend(FakePlatformBackend):
+  def __init__(self):
+    super(FakeAndroidPlatformBackend, self).__init__()
+    self.device = 'fake_device'
+
+  def GetOSName(self):
+    return 'android'
+
+
+class FakeDesktopPlatformBackend(FakePlatformBackend):
+  def __init__(self):
+    self.platform = 'win'
+
+  def GetOSName(self):
+    return self.platform
 
 
 class FakeBattOr(object):
@@ -82,10 +103,8 @@
     battery_utils.BatteryUtils = FakeBatteryUtils
 
     # Agents and backends.
-    self.android_backend = fakes.FakePlatform()
-    self.android_backend.SetOSName('android')
-    self.desktop_backend = fakes.FakePlatform()
-    self.desktop_backend.SetOSName('win')
+    self.android_backend = FakeAndroidPlatformBackend()
+    self.desktop_backend = FakeDesktopPlatformBackend()
     self.android_agent = (
         battor_tracing_agent.BattOrTracingAgent(self.android_backend))
     self.desktop_agent = (
@@ -96,9 +115,10 @@
     battery_utils.BatteryUtils = self._battery_utils
 
   def testInit(self):
-    self.assertEqual(
-        self.android_agent._platform_backend.GetOSName(), 'android')
-    self.assertEqual(self.desktop_agent._platform_backend.GetOSName(), 'win')
+    self.assertTrue(isinstance(self.android_agent._platform_backend,
+                               FakeAndroidPlatformBackend))
+    self.assertTrue(isinstance(self.desktop_agent._platform_backend,
+                               FakeDesktopPlatformBackend))
 
   def testIsSupportedAndroid(self):
     self.assertTrue(battor_tracing_agent.BattOrTracingAgent.IsSupported(