Make it possible to switch between two different versions of ANGLE.

webkit/common/gpu/webkit_gpu.gyp

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'conditions': [
     # TODO(stuartmorgan): All dependencies from code built on iOS to
     # webkit/ should be removed, at which point this condition can be
     # removed.
     ['OS != "ios"', {
       'targets': [
         {
           'target_name': 'webkit_gpu',
           'type': '<(component)',
           'variables': { 'enable_wexit_time_destructors': 1, },
           'dependencies': [
             '<(DEPTH)/base/base.gyp:base',
             '<(DEPTH)/base/third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
             '<(DEPTH)/gpu/command_buffer/command_buffer.gyp:gles2_utils',
             '<(DEPTH)/gpu/gpu.gyp:command_buffer_client',
             '<(DEPTH)/gpu/gpu.gyp:command_buffer_service',
             '<(DEPTH)/gpu/gpu.gyp:gles2_c_lib',
             '<(DEPTH)/gpu/gpu.gyp:gles2_implementation',
             '<(DEPTH)/skia/skia.gyp:skia',
             '<(DEPTH)/third_party/WebKit/public/blink.gyp:blink',
-            '<(DEPTH)/third_party/angle/src/build_angle.gyp:translator_glsl',
+            '<(angle_path)/src/build_angle.gyp:translator_glsl',
             '<(DEPTH)/ui/gl/gl.gyp:gl',
             '<(DEPTH)/ui/ui.gyp:ui',
           ],
           'sources': [
             # This list contains all .h and .cc in gpu except for test code.
             'context_provider_in_process.cc',
             'context_provider_in_process.h',
             'gl_bindings_skia_cmd_buffer.cc',
             'gl_bindings_skia_cmd_buffer.h',
             'grcontext_for_webgraphicscontext3d.cc',
@@ skipping 10 matching lines @@
           'defines': [
             'WEBKIT_GPU_IMPLEMENTATION',
           ],
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         },
       ],
     }],
   ],
 }