Change build.py to be like ninja.py and only use a single GN/Ninja invocation to cross-build the SD…

tools/build.py

Index: tools/build.py
diff --git a/tools/build.py b/tools/build.py
index 29c081f38998dfbdcf773ef1004c1eb2f25fca0c..5fa9f22ae83530033753fa3482184f6767bb3c8c 100755
--- a/tools/build.py
+++ b/tools/build.py
@@ -482,7 +482,7 @@ def BuildNinjaCommand(options, target, target_os, mode, arch):
 
 
 filter_xcodebuild_output = False
-def BuildOneConfig(options, target, target_os, mode, arch, override_tools):
+def BuildOneConfig(options, target, target_os, mode, arch):
   global filter_xcodebuild_output
   start_time = time.time()
   args = []
@@ -588,41 +588,6 @@ def BuildOneConfig(options, target, target_os, mode, arch, override_tools):
   return 0
 
 
-def BuildCrossSdk(options, target_os, mode, arch):
-  # First build 'create_sdk' for the host. Do not override the host toolchain.
-  if BuildOneConfig(options, 'create_sdk', HOST_OS,
-                    mode, HOST_ARCH, False) != 0:
-    return 1
-
-  # Then, build the runtime for the target arch.
-  if BuildOneConfig(options, 'runtime', target_os, mode, arch, True) != 0:
-    return 1
-
-  # Copy dart-sdk from the host build products dir to the target build
-  # products dir, and copy the dart binary for target to the sdk bin/ dir.
-  src = os.path.join(
-      utils.GetBuildRoot(HOST_OS, mode, HOST_ARCH, HOST_OS), 'dart-sdk')
-  dst = os.path.join(
-      utils.GetBuildRoot(HOST_OS, mode, arch, target_os), 'dart-sdk')
-  shutil.rmtree(dst, ignore_errors=True)
-  shutil.copytree(src, dst)
-
-  dart = os.path.join(
-      utils.GetBuildRoot(HOST_OS, mode, arch, target_os), 'dart')
-  bin = os.path.join(dst, 'bin')
-  shutil.copy(dart, bin)
-
-  # Strip the dart binary
-  toolchainprefix = GetToolchainPrefix(target_os, arch, options)
-  if toolchainprefix == None:
-    print "Couldn't figure out the cross-toolchain"
-    return 1
-  strip = toolchainprefix + '-strip'
-  subprocess.call([strip, os.path.join(bin, 'dart')])
-
-  return 0
-
-
 def Main():
   utils.ConfigureJava()
   # Parse the options.
@@ -642,14 +607,9 @@ def Main():
     for target_os in options.os:
       for mode in options.mode:
         for arch in options.arch:
-          cross_build = utils.IsCrossBuild(target_os, arch)
-          if target in ['create_sdk'] and cross_build:
-            if BuildCrossSdk(options, target_os, mode, arch) != 0:
-              return 1
-          else:
-            if BuildOneConfig(options, target, target_os,
-                              mode, arch, cross_build) != 0:
-              return 1
+          if BuildOneConfig(options, target, target_os,
+                            mode, arch) != 0:
+            return 1
 
   return 0