Add support to run emulator without ui on bots

build/android/pylib/utils/emulator.py

Index: build/android/pylib/utils/emulator.py
diff --git a/build/android/pylib/utils/emulator.py b/build/android/pylib/utils/emulator.py
index abd0cb64246b20d3816349e028f6b3ceb8865e50..4007f1a2d3059553a65200be31e5ff276d6d8470 100644
--- a/build/android/pylib/utils/emulator.py
+++ b/build/android/pylib/utils/emulator.py
@@ -158,7 +158,8 @@ def _GetAvailablePort():
 
 def LaunchTempEmulators(emulator_count, abi, api_level, enable_kvm=False,
                         kill_and_launch=True, sdcard_size=DEFAULT_SDCARD_SIZE,
-                        storage_size=DEFAULT_STORAGE_SIZE, wait_for_boot=True):
+                        storage_size=DEFAULT_STORAGE_SIZE, wait_for_boot=True,
+                        headless=False):
   """Create and launch temporary emulators and wait for them to boot.
 
   Args:
@@ -166,6 +167,7 @@ def LaunchTempEmulators(emulator_count, abi, api_level, enable_kvm=False,
     abi: the emulator target platform
     api_level: the api level (e.g., 19 for Android v4.4 - KitKat release)
     wait_for_boot: whether or not to wait for emulators to boot up
+    headless: running emulator with no ui
 
   Returns:
     List of emulators.
@@ -178,7 +180,8 @@ def LaunchTempEmulators(emulator_count, abi, api_level, enable_kvm=False,
     logging.info('Emulator launch %d with avd_name=%s and api=%d',
         n, avd_name, api_level)
     emulator = Emulator(avd_name, abi, enable_kvm=enable_kvm,
-                        sdcard_size=sdcard_size, storage_size=storage_size)
+                        sdcard_size=sdcard_size, storage_size=storage_size,
+                        headless=headless)
     emulator.CreateAVD(api_level)
     emulator.Launch(kill_all_emulators=(n == 0 and kill_and_launch))
     t.Stop()
@@ -192,19 +195,21 @@ def LaunchTempEmulators(emulator_count, abi, api_level, enable_kvm=False,
 
 def LaunchEmulator(avd_name, abi, kill_and_launch=True, enable_kvm=False,
                    sdcard_size=DEFAULT_SDCARD_SIZE,
-                   storage_size=DEFAULT_STORAGE_SIZE):
+                   storage_size=DEFAULT_STORAGE_SIZE, headless=False):
   """Launch an existing emulator with name avd_name.
 
   Args:
     avd_name: name of existing emulator
     abi: the emulator target platform
+    headless: running emulator with no ui
 
   Returns:
     emulator object.
   """
   logging.info('Specified emulator named avd_name=%s launched', avd_name)
   emulator = Emulator(avd_name, abi, enable_kvm=enable_kvm,
-                      sdcard_size=sdcard_size, storage_size=storage_size)
+                      sdcard_size=sdcard_size, storage_size=storage_size,
+                      headless=headless)
   emulator.Launch(kill_all_emulators=kill_and_launch)
   emulator.ConfirmLaunch(True)
   return emulator
@@ -242,7 +247,7 @@ class Emulator(object):
 
   def __init__(self, avd_name, abi, enable_kvm=False,
                sdcard_size=DEFAULT_SDCARD_SIZE,
-               storage_size=DEFAULT_STORAGE_SIZE):
+               storage_size=DEFAULT_STORAGE_SIZE, headless=False):
     """Init an Emulator.
 
     Args:
@@ -259,6 +264,7 @@ class Emulator(object):
     self.sdcard_size = sdcard_size
     self.storage_size = storage_size
     self.enable_kvm = enable_kvm
+    self.headless = headless
 
   @staticmethod
   def _DeviceName():
@@ -375,13 +381,22 @@ class Emulator(object):
         self.emulator,
         # Speed up emulator launch by 40%.  Really.
         '-no-boot-anim',
+        ]
+    if self.headless:
+      emulator_command.extend([
+        '-no-skin',
+        '-no-audio',
+        '-no-window'
+        ])
+    emulator_command.extend([
         # Use a familiar name and port.
         '-avd', self.avd_name,
         '-port', str(port),
         # Enable GPU by default.
         '-gpu', 'on',
+        # all the argument after qemu are sub arguments for qemu
         '-qemu', '-m', '1024',
-        ]
+        ])
     if self.abi == 'x86' and self.enable_kvm:
       emulator_command.extend([
           # For x86 emulator --enable-kvm will fail early, avoiding accidental