Print dumped json in generate_compdb.py

print shows u prefix in string (e.g u"directory").

I also updated clang_tidy docs to change directory for compile_commands.json.

Change-Id: I5e801519e7856feab2d32ac1ec6062687f0156b0
Reviewed-on: https://chromium-review.googlesource.com/1025491
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#553041}

docs/clang_tidy.md

@@ -53,7 +53,7 @@ ninja -C out/Release chrome
 ```
 2.  Generate the compilation database
 ```
-tools/clang/scripts/generate_compdb.py -p out/Release > compile_commands.json
+tools/clang/scripts/generate_compdb.py -p out/Release > out/Release/compile_commands.json
 ```
 3.  Enter the build directory.
 ```
@@ -62,7 +62,7 @@ cd out/Release
 4.  Run clang-tidy.
 ```
 <PATH_TO_LLVM_SRC>/tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py \
-    -p ../.. \# Set the root project directory, where compile_commands.json is.
+    -p . \# Set the root project directory, where compile_commands.json is.
     # Set the clang-tidy binary path, if it's not in your $PATH.
     -clang-tidy-binary <PATH_TO_LLVM_BUILD>/bin/clang-tidy \
     # Set the clang-apply-replacements binary path, if it's not in your $PATH
@@ -77,7 +77,7 @@ cd out/Release
 
 Copy-Paste Friendly (though you'll still need to stub in the variables):
 <PATH_TO_LLVM_SRC>/tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py \
-    -p ../.. \
+    -p . \
     -clang-tidy-binary <PATH_TO_LLVM_BUILD>/bin/clang-tidy \
     -clang-apply-replacements-binary \
         <PATH_TO_LLVM_BUILD>/bin/clang-apply-replacements \

tools/clang/scripts/generate_compdb.py

@@ -11,6 +11,7 @@ mode, etc.
 """
 
 import argparse
+import json
 import os
 import sys
 
@@ -29,7 +30,7 @@ def main(argv):
       help='Path to build directory')
   args = parser.parse_args()
 
-  print compile_db.GenerateWithNinja(args.p)
+  print json.dumps(compile_db.GenerateWithNinja(args.p))
 
 
 if __name__ == '__main__':