Use raw strings for javac colorize regexes

Particularly the '\\' in fileline_prefix would need to be '\\\\' in a
normal (non-raw) python string.

NOTRY=true

Review URL: https://codereview.chromium.org/330573003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@276748 0039d316-1c4b-4281-b951-d872f2087c98

build/android/gyp/javac.py

@@ -18,11 +18,11 @@ import colorama
 
 
 def ColorJavacOutput(output):
-  fileline_prefix = '(?P<fileline>(?P<file>[-.\w/\\]+.java):(?P<line>[0-9]+):)'
+  fileline_prefix = r'(?P<fileline>(?P<file>[-.\w/\\]+.java):(?P<line>[0-9]+):)'
   warning_re = re.compile(
-      fileline_prefix + '(?P<full_message> warning: (?P<message>.*))$')
+      fileline_prefix + r'(?P<full_message> warning: (?P<message>.*))$')
   error_re = re.compile(
-      fileline_prefix + '(?P<full_message> (?P<message>.*))$')
+      fileline_prefix + r'(?P<full_message> (?P<message>.*))$')
   marker_re = re.compile(r'\s*(?P<marker>\^)\s*$')
 
   warning_color = ['full_message', colorama.Fore.YELLOW + colorama.Style.DIM]