[Fuchsia] Make Fuchsia device connection retry for a full minute.

Remove retry attempt limit, instead keep retrying to connect to device for a minute.
Fuchsia bug: https://bugs.fuchsia.dev/p/fuchsia/issues/detail?id=45090

Change-Id: I0c424fa4d63ffa457c50487261ad37ab97092d3c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2033909
Commit-Queue: Chong Gu <chonggu@google.com>
Reviewed-by: Kevin Marshall <kmarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737553}

build/fuchsia/target.py

@@ -16,8 +16,8 @@ import time
 
 
 _SHUTDOWN_CMD = ['dm', 'poweroff']
-_ATTACH_MAX_RETRIES = 10
 _ATTACH_RETRY_INTERVAL = 1
+_ATTACH_RETRY_SECONDS = 60
 
 # Amount of time to wait for Amber to complete package installation, as a
 # mitigation against hangs due to amber/network-related failures.
@@ -206,11 +206,12 @@ class Target(object):
   def _AssertIsStarted(self):
     assert self.IsStarted()
 
-  def _WaitUntilReady(self, retries=_ATTACH_MAX_RETRIES):
+  def _WaitUntilReady(self):
     logging.info('Connecting to Fuchsia using SSH.')
 
-    for retry in xrange(retries + 1):
     host, port = self._GetEndpoint()
+    end_time = time.time() + _ATTACH_RETRY_SECONDS
+    while time.time() < end_time:
       runner = remote_cmd.CommandRunner(self._GetSshConfigPath(), host, port)
       if runner.RunCommand(['true'], True) == 0:
         logging.info('Connected!')
@@ -262,4 +263,3 @@ class Target(object):
                                        timeout_secs=_INSTALL_TIMEOUT_SECS)
         if return_code != 0:
           raise Exception('Error while installing %s.' % install_package_name)
-