docs: Fix links by not putting whitespace inside them.

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 21 matching lines @@
 
 ## Writing the tool
 
 LLVM uses C++11 and CMake. Source code for Chromium clang tools lives in
 [//tools/clang](https://chromium.googlesource.com/chromium/src/tools/clang/+/master).
 It is generally easiest to use one of the already-written tools as the base for
 writing a new tool.
 
 Chromium clang tools generally follow this pattern:
 
-1.  Instantiate a [`clang::ast_matchers::MatchFinder`](
-    http://clang.llvm.org/doxygen/classclang_1_1ast__matchers_1_1MatchFinder.html).
-2.  Call `addMatcher()` to register [`clang::ast_matchers::MatchFinder::MatchCallback`](
-    http://clang.llvm.org/doxygen/classclang_1_1ast__matchers_1_1MatchFinder_1_1MatchCallback.html) actions to execute when [matching](http://clang.llvm.org/docs/LibASTMatchersReference.html) the AST.
+1.  Instantiate a [`clang::ast_matchers::MatchFinder`](http://clang.llvm.org/doxygen/classclang_1_1ast__matchers_1_1MatchFinder.html).
+2.  Call `addMatcher()` to register [`clang::ast_matchers::MatchFinder::MatchCallback`](http://clang.llvm.org/doxygen/classclang_1_1ast__matchers_1_1MatchFinder_1_1MatchCallback.html)
+    actions to execute when [matching](http://clang.llvm.org/docs/LibASTMatchersReference.html)
+    the AST.
 3.  Create a new `clang::tooling::FrontendActionFactory` from the `MatchFinder`.
 4.  Run the action across the specified files with
     [`clang::tooling::ClangTool::run`](http://clang.llvm.org/doxygen/classclang_1_1tooling_1_1ClangTool.html#acec91f63b45ac7ee2d6c94cb9c10dab3).
-5.  Serialize generated [`clang::tooling::Replacement`](
-    http://clang.llvm.org/doxygen/classclang_1_1tooling_1_1Replacement.html)s to
-    `stdout`.
+5.  Serialize generated [`clang::tooling::Replacement`](http://clang.llvm.org/doxygen/classclang_1_1tooling_1_1Replacement.html)s
+    to `stdout`.
 
 Other useful references when writing the tool:
 
 *   [Clang doxygen reference](http://clang.llvm.org/doxygen/index.html)
 *   [Tutorial for building tools using LibTooling and LibASTMatchers](http://clang.llvm.org/docs/LibASTMatchersTutorial.html)
 
 ### Edit serialization format
 ```
 ==== BEGIN EDITS ====
 r:::path/to/file1:::offset1:::length1:::replacement text
@@ skipping 16 matching lines @@
     knows to translate `\0` back to newlines when applying edits.
 *   When removing an element from a 'list' (e.g. function parameters,
     initializers), the tool should emit a deletion for just the element. The
     script understands how to extend the deletion to remove commas, etc. as
     needed.
 
 TODO: Document more about `SourceLocation` and how spelling loc differs from
 expansion loc, etc.
 
 ### Why not RefactoringTool?
-While clang has a [`clang::tooling::RefactoringTool`](
-http://clang.llvm.org/doxygen/classclang_1_1tooling_1_1RefactoringTool.html) to
-automatically apply the generated replacements and save the results, it doesn't
-work well for Chromium:
+While clang has a [`clang::tooling::RefactoringTool`](http://clang.llvm.org/doxygen/classclang_1_1tooling_1_1RefactoringTool.html)
+to automatically apply the generated replacements and save the results, it
+doesn't work well for Chromium:
 
 *   Clang tools run actions serially, so runtime scales poorly to tens of
     thousands of files.
 *   A parsing error in any file (quite common in NaCl source) prevents any of
     the generated replacements from being applied.
 
 ## Building
 Synopsis:
+
 ```shell
 tools/clang/scripts/update.py --force-local-build --without-android \
   --tools blink_gc_plugin plugins rewrite_to_chrome_style
 ```
+
 Running this command builds the [Oilpan plugin](https://chromium.googlesource.com/chromium/src/+/master/tools/clang/blink_gc_plugin/),
 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.
 
 ## 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:
 ```
 tools/clang/scripts/run_tool.py <toolname> \
   --generate-compdb
   out/Debug <path 1> <path 2> ...
 ```
@@ skipping 38 matching lines @@
 Synposis:
 ```shell
 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`.