Add net log to UploadDataStream.

tools/clang/scripts/update.py

Index: tools/clang/scripts/update.py
diff --git a/tools/clang/scripts/update.py b/tools/clang/scripts/update.py
index 07f61f1da0e12fb78f64db1b8fe058a7f09b1cf0..bf417a57e573ec8ed324d37466e36ac16a6d9415 100755
--- a/tools/clang/scripts/update.py
+++ b/tools/clang/scripts/update.py
@@ -27,7 +27,7 @@ import zipfile
 # Do NOT CHANGE this if you don't know what you're doing -- see
 # https://chromium.googlesource.com/chromium/src/+/master/docs/updating_clang.md
 # Reverting problematic clang rolls is safe, though.
-CLANG_REVISION = '277962'
+CLANG_REVISION = '274369'
 
 use_head_revision = 'LLVM_FORCE_HEAD_REVISION' in os.environ
 if use_head_revision:
@@ -71,7 +71,7 @@ BINUTILS_BIN_DIR = os.path.join(BINUTILS_DIR, BINUTILS_DIR,
                                 'Linux_x64', 'Release', 'bin')
 BFD_PLUGINS_DIR = os.path.join(BINUTILS_DIR, 'Linux_x64', 'Release',
                                'lib', 'bfd-plugins')
-VERSION = '4.0.0'
+VERSION = '3.9.0'
 ANDROID_NDK_DIR = os.path.join(
     CHROMIUM_DIR, 'third_party', 'android_tools', 'ndk')