Revert "Use the same Clang revision as v8 uses"

README.md

 # PDFium
 
 ## News
 
-As of 2016-02-04, the XFA branch is deprecated.  Instead, see
-[the section on configuration](#BuildConfig) below.
-
-As of 2016-04-15, Visual Studio toolchain from depot_tools will be used as the
-default. Set DEPOT_TOOLS_WIN_TOOLCHAIN=0 if you need to use system toolchain.
-See [Windows development subsection](#WinDev) for details.
-
+As of 2016-02-04, the XFA branch is deprecated.  Instead, see the section on
+configuration below.
 
 ## Prerequisites
 
 Get the chromium depot tools via the instructions at
 http://www.chromium.org/developers/how-tos/install-depot-tools (this provides
 the gclient utilty needed below).
 
 Also install Python, Subversion, and Git and make sure they're in your path.
 
-###<a name="WinDev"></a> Windows development
-
-PDFium uses similar Windows toolchain as Chromium:
-
-#### Open source contributors:
-Visual Studio 2015 Update 2 or later is highly recommended.
-
-Run `set DEPOT_TOOLS_WIN_TOOLCHAIN=0`, or set that variable in your global
-environment.
-
-Compilation is done through ninja, **not** Visual Studio.
-
-#### Google employees
-
-Run: `download_from_google_storage --config` and follow the
-authentication instructions. **Note that you must authenticate with your
-@google.com credentials**. Enter "0" if asked for a project-id.
-
-Once you've done this, the toolchain will be installed automatically for
-you in Step 3, below (near the end of the step).
-
-The toolchain will be in `depot_tools\win_toolchain`, and windbg can be
-found in `depot_tools\win_toolchain\vs2013_files\win8sdk\Debuggers`.
-
-If you want the IDE for debugging and editing, you will need to install
-it separately, but this is optional and not needed to build PDFium.
-
-
 ## Get the code
 
 The name of the top-level directory does not matter. In our examples, we use
 "repo". This directory must not have been used before by `gclient config` as
 each directory can only house a single gclient configuration.
 
 ```
 mkdir repo
 cd repo
 gclient config --unmanaged https://pdfium.googlesource.com/pdfium.git
@@ skipping 13 matching lines @@
 (http://build.chromium.org/p/client.pdfium/).
 
  * On Windows: `build\gyp_pdfium`
  * For all other platforms: `build/gyp_pdfium`
 
 The second option is to generate platform-specific build files, i.e. Makefiles
 on Linux, sln files on Windows, and xcodeproj files on Mac. To do so, set the
 GYP\_GENERATORS environment variable appropriately (e.g. "make", "msvs", or
 "xcode") before running the above command.
 
-###<a name="BuildConfig"></a> Selecting build configuration
+### Selecting build configuration
 
 PDFium may be built either with or without JavaScript support, and with
 or without XFA forms support.  Both of these features are enabled by
 default. Also note that the XFA feature requires JavaScript.
 
 To build without XFA, set `pdf_enable_xfa=0` before running `gyp_pdfium`.
 To build without JavaScript, set `pdf_enable_v8=0 pdf_enable_xfa=0` before
 running `gyp_pdfium`. For example
 ```
 GYP_DEFINES='pdf_enable_v8=0 pdf_enable_xfa=0' build/gyp_pdfium
@@ skipping 74 matching lines @@
 as much as possible. The main exceptions is:
 
 1. Code has to conform to the existing style and not Chromium/Google style.
 
 ## Branches
 
 Prior to 2016-02-04, there existed an actively developed origin/xfa branch.
 The origin/xfa branch is now an evolutionary dead-end. Everything you need
 to build either with or without the XFA feature is on origin/master.