Add a gyp flag to allow removing dependency on ppapi.

content/content_common.gypi

 # Copyright (c) 2012 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../build/temp_gyp/googleurl.gyp:googleurl',
     '../media/media.gyp:media',
     '../net/net.gyp:net',
@@ skipping 396 matching lines @@
         ['include', '^common/savable_url_schemes\\.cc$'],
         ['include', '^common/url_schemes\\.cc$'],
       ],
     }, {  # OS!="ios"
       'dependencies': [
         '../cc/cc.gyp:cc',
         '../gpu/gpu.gyp:gles2_implementation',
         '../gpu/gpu.gyp:gpu_ipc',
         '../ipc/ipc.gyp:ipc',
         '../media/media.gyp:shared_memory_support',
-        '../ppapi/ppapi_internal.gyp:ppapi_shared',
         '../third_party/npapi/npapi.gyp:npapi',
         '<(webkit_src_dir)/Source/WebKit/chromium/WebKit.gyp:webkit',
         '../ui/gl/gl.gyp:gl',
         '../webkit/support/webkit_support.gyp:glue',
         '../webkit/support/webkit_support.gyp:webkit_base',
         '../webkit/support/webkit_support.gyp:webkit_storage',
       ],
     }],
     ['OS!="win"', {
       'sources!': [
@@ skipping 29 matching lines @@
           '-lXcomposite',
         ],
       },
     }],
     ['use_x11 == 1 and (target_arch != "arm" or chromeos == 0)', {
       'sources': [
         'common/gpu/x_util.cc',
         'common/gpu/x_util.h',
       ],
     }],
+    ['enable_ppapi==1', {
+      'dependencies': [
+        '../ppapi/ppapi_internal.gyp:ppapi_shared',
+      ],
+    }],
     ['enable_gpu==1', {
       'dependencies': [
         '../gpu/gpu.gyp:command_buffer_service',
       ],
     }],
     ['target_arch=="arm" and chromeos == 1', {
       'dependencies': [
         '../media/media.gyp:media',
       ],
       'sources': [
@@ skipping 82 matching lines @@
         '../build/extract_from_cab.py',
         '..\\third_party\\directxsdk\\files\\Redist\\<(input)',
         '<(output)',
         '<(PRODUCT_DIR)',
         ],
       },
      ]
     }],
   ],
 }