Skip parameter replacements where old text != old name.

docs/clang_tool_refactoring.md

 # Clang Tool Refactoring
 
 [TOC]
 
 ## Introduction
 
 Clang tools can help with global refactorings of Chromium code. Clang tools can
 take advantage of clang's AST to perform refactorings that would be impossible
 with a traditional find-and-replace regexp:
 
@@ skipping 94 matching lines @@
 the [Chrome style
 plugin](https://chromium.googlesource.com/chromium/src/+/master/tools/clang/plugins/),
 and the [Blink to Chrome style rewriter](https://chromium.googlesource.com/chromium/src/+/master/tools/clang/rewrite_to_chrome_style/). Additional arguments to `--tools` should be the name of
 subdirectories in
 [//tools/clang](https://chromium.googlesource.com/chromium/src/+/master/tools/clang).
 Generally, `--tools` should always include `blink_gc_plugin` and `plugins`: otherwise, Chromium won't build.
 
 It is important to use --bootstrap as there appear to be [bugs](https://crbug.com/580745)
 in the clang library this script produces if you build it with gcc, which is the default.
 
+After bootstrapping is done, rebuilding can be done with something like:
+
+```shell
+ninja -C third_party/llvm-build/Release+Asserts <tool name>
+```

[dcheng, 2016/08/25 04:08:51]

Let's leave this out, it's a convenient shortcut but a bit fragile (similar to
how GYP + ninja was fragile). Hopefully we'll have something better in the
future.

[Łukasz Anforowicz, 2016/08/25 23:32:33]

Done.

+
 ## Running
 First, build all chromium targets to avoid failures due to missing dependecies
 that are generated as part of the build:
 
 ```shell
 ninja -C out/Debug
 ```
 
 Then run the actual tool:
 
@@ skipping 40 matching lines @@
   stmt->dumpColor();
 ```
 
 By default, the script hides the output of the tool. The easiest way to change
 that is to `return 1` from the `main()` function of the clang tool.
 
 ## Testing
 Synposis:
 
 ```shell
-test_tool.py <tool name>
+tools/clang/scripts/test_tool.py <tool name>
 ```
 
 The name of the tool binary and the subdirectory for the tool in
 `//tools/clang` must match. The test runner finds all files that match the
 pattern `//tools/clang/<tool name>/tests/*-original.cc`, runs the tool across
 those files, and compared it to the `*-expected.cc` version. If there is a
 mismatch, the result is saved in `*-actual.cc`.