Implement clang tool that converts std::string("") to std::string().

tools/clang/scripts/update.sh

Index: tools/clang/scripts/update.sh
diff --git a/tools/clang/scripts/update.sh b/tools/clang/scripts/update.sh
index ed316be8c153f1458b0c4558ba239e7483c337c4..f6838015bde59605204e7e9dbc45ebdba16046da 100755
--- a/tools/clang/scripts/update.sh
+++ b/tools/clang/scripts/update.sh
@@ -375,7 +375,7 @@ fi
 
 # Build Chrome-specific clang tools. Paths in this list should be relative to
 # tools/clang.
-CHROME_TOOL_DIRS="plugins"
+CHROME_TOOL_DIRS="empty_string plugins"

[Nico, 2013/03/27 16:35:29]

Hm, this means that everyone building clang locally will build lots of tools
over time. Maybe there could be a build-tool $toolname script instead, which
does the stuff below? Then people who want to use a tool can call that for the
tool they care about, and update.sh could call it to build the plugin.

[dcheng, 2013/03/28 00:10:17]

I added (another) command-line argument instead, so I can just use $LLVM_DIR and
${NUM_JOBS}. It defaults to just plugins so people who don't care about tooling
can just omit the argument completely.

 # For each tool directory, copy it into the clang tree and use clang's build
 # system to compile it.
 for CHROME_TOOL_DIR in ${CHROME_TOOL_DIRS}; do