Fix logic in PerfProfiler.is_supported.

tools/telemetry/telemetry/core/platform/profiler/perf_profiler.py

Index: tools/telemetry/telemetry/core/platform/profiler/perf_profiler.py
diff --git a/tools/telemetry/telemetry/core/platform/profiler/perf_profiler.py b/tools/telemetry/telemetry/core/platform/profiler/perf_profiler.py
index 3a0652b54a2aca8f2cb6bf5cfcd50c15d9df2f98..ac2c2ba7434811c880bedc2b248f3dacab30199a 100644
--- a/tools/telemetry/telemetry/core/platform/profiler/perf_profiler.py
+++ b/tools/telemetry/telemetry/core/platform/profiler/perf_profiler.py
@@ -14,6 +14,7 @@ from pylib.device import device_errors  # pylint: disable=F0401
 
 from telemetry.core import platform
 from telemetry.core import util
+from telemetry.core.backends.chrome import cros_interface
 from telemetry.core.platform import profiler
 from telemetry.core.platform.profiler import android_profiling_helper
 from telemetry.util import support_binaries
@@ -199,7 +200,7 @@ class PerfProfiler(profiler.Profiler):
   def is_supported(cls, browser_type):
     if sys.platform != 'linux2':
       return False
-    if browser_type.startswith('cros'):
+    if cros_interface.IsRunningOnCrosDevice():
       return False
     return True