Remove pointless TODO comments someone added.

During the wiki->docs/*.md conversion, someone added a bunch of TODO
comments and then never acted on them.  Since having TODOs in documentation
is pretty gross and since the TODOs don't make much sense, remove them.

BUG=none
R=hans@chromium.org

Review URL: https://codereview.chromium.org/1636073003 .

Cr-Commit-Position: refs/heads/master@{#371532}

docs/updating_clang_format_binaries.md

@@ -76,8 +76,6 @@ strip bin/clang-format
 -DCMAKE_C_COMPILER=$PWD/../chrome/src/third_party/llvm-build/Release+Asserts/bin/clang -DCMAKE_CXX_COMPILER=$PWD/../chrome/src/third_party/llvm-build/Release+Asserts/bin/clang++
 ```
 
-TODO: these ^^ instructions looks odd. Are they correct???
-
 Platform specific notes:
 
 *   Windows: Visual Studio 2013 only.

docs/writing_clang_plugins.md

@@ -2,11 +2,6 @@
 
 [TOC]
 
-TODO: although cs.chromium.org
-[finds](https://code.google.com/p/chromium/codesearch#chromium/src/third_party/llvm/)
-`src/third_party/llvm`, it
-[does not exist in Gitiles](https://chromium.googlesource.com/src/third_party/llvm/).
-
 Make sure you really want to write a clang plugin.
 
 *   The clang plugin api is not stable. If you write a plugin, _you_ are