Add support for decoding WebP images

ios/web/ios_web.gyp

 # Copyright 2014 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.
 
 {
   'variables': {
     'chromium_code': 1,
    },
   'targets': [
     {
       'target_name': 'ios_web',
       'type': 'static_library',
       'include_dirs': [
         '../..',
       ],
       'dependencies': [
+        'webp_decoder',
         '../../base/base.gyp:base',
         '../../content/content.gyp:content_browser',
         '../../net/net.gyp:net',
         '../../ui/base/ui_base.gyp:ui_base',
         '../../ui/gfx/gfx.gyp:gfx',
       ],
       'sources': [
         'browser_state.cc',
         'load_committed_details.cc',
         'navigation/navigation_item_impl.h',
@@ skipping 11 matching lines @@
         'public/user_agent.h',
         'public/user_agent.mm',
         'public/web_state/web_state_observer.h',
         'public/web_thread.h',
         'string_util.cc',
         'web_state/web_state_observer.cc',
         'web_thread.cc',
       ],
     },
     {
+      'target_name': 'webp_decoder',
+      'type': 'static_library',
+      'include_dirs': [
+        '../..',
+      ],
+      'dependencies': [
+        '../../base/base.gyp:base',
+        '../../third_party/libwebp/libwebp.gyp:libwebp_dec',
+      ],
+      'sources': [
+        'public/webp_decoder.h',
+        'public/webp_decoder.mm',
+      ],
+    },
+    {
       'target_name': 'test_support_ios_web',
       'type': 'static_library',
       'dependencies': [
         'ios_web',
       ],
       'include_dirs': [
         '../..',
       ],
       'sources': [
         'public/test/test_browser_state.cc',
         'public/test/test_browser_state.h',
         'public/test/test_web_state.cc',
         'public/test/test_web_state.h',
       ],
     },
   ],
 }