Tweak some of the commands in the "Updating clang-format binaries" doc

docs/updating_clang_format_binaries.md

 # Updating Clang format binaries
 
 Instructions on how to update the [clang-format binaries](clang_format.md) that
 come with a checkout of Chromium.
 
 ## Prerequisites
 
 You'll need a Windows machine, a Linux machine, and a Mac; all capable of
 building clang-format. You'll also need permissions to upload to the appropriate
 google storage bucket. Chromium infrastructure team members have this, and
@@ skipping 10 matching lines @@
 
 Follow the official instructions here:
 http://clang.llvm.org/get_started.html.
 
 Windows step-by-step:
 
 ```shell
 # [double check you have the tools you need]
 where cmake.exe  # You need to install this.
 where svn.exe  # Maybe fix with: set PATH=%PATH%;D:\src\depot_tools\svn_bin
-"c:\Program Files (x86)\Microsoft Visual Studio 12.0\vc\vcvarsall.bat" amd64_x86
+"c:\Program Files (x86)\Microsoft Visual Studio 14.0\vc\vcvarsall.bat" amd64_x86
 
 set CLANG_REV=198831  # You must change this value (see above)
 
 [from a clean directory, check out and build]
 rmdir /S /Q llvm
 rmdir /S /Q llvm-build
 mkdir llvm
 mkdir llvm-build
 svn co http://llvm.org/svn/llvm-project/llvm/trunk@%CLANG_REV% llvm
 cd llvm\tools
 svn co http://llvm.org/svn/llvm-project/cfe/trunk@%CLANG_REV% clang
 cd ..\..\llvm-build
 set CC=cl
 set CXX=cl
-cmake -G Ninja ..\llvm -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_CRT_RELEASE=MT \
-    -DLLVM_ENABLE_ASSERTIONS=NO -DLLVM_ENABLE_THREADS=NO \
+cmake -G Ninja ..\llvm -DCMAKE_BUILD_TYPE=Release -DLLVM_USE_CRT_RELEASE=MT ^
+    -DLLVM_ENABLE_ASSERTIONS=NO -DLLVM_ENABLE_THREADS=NO ^
     -DPYTHON_EXECUTABLE=d:\src\depot_tools\python276_bin\python.exe
 ninja clang-format
 bin\clang-format.exe --version
 ```
 
 Mac & Linux step-by-step:
 
 ```shell
 # Check out.
 export CLANG_REV=198831   # You must change this value (see above)
 rm -rf llvm
 rm -rf llvm-build
 mkdir llvm
 mkdir llvm-build
 svn co http://llvm.org/svn/llvm-project/llvm/trunk@$CLANG_REV llvm
 cd llvm/tools
 svn co http://llvm.org/svn/llvm-project/cfe/trunk@$CLANG_REV clang
 cd ../../llvm-build
 
 # Option 1: with cmake
-MACOSX_DEPLOYMENT_TARGET=10.9 cmake -G Ninja  -DCMAKE_BUILD_TYPE=Release \
+MACOSX_DEPLOYMENT_TARGET=10.9 cmake -G Ninja -DCMAKE_BUILD_TYPE=Release \
     -DLLVM_ENABLE_ASSERTIONS=NO -DLLVM_ENABLE_THREADS=NO ../llvm/
 time caffeinate ninja clang-format
 strip bin/clang-format
 
 # (On Linux, to build with clang, which produces smaller binaries, add this to
 # your cmake invocation.
 # On Mac, the system compiler is already clang so it's not needed there.)
 -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++
 ```
 
@@ skipping 36 matching lines @@
     The binaries were built at clang revision ####### on ####DATETIME####.
 
     BUG=
 
 The change should **always** include new `.sha1` files for each platform (we
 want to keep these in lockstep), should **never** include `clang-format`
 binaries directly. The change should **always** update `README.chromium`
 
 clang-format binaries should weigh in at 1.5MB or less. Watch out for size
 regressions.