Allow for building content_shell from within WebKit

content/browser/debugger/devtools_resources.gyp

Index: content/browser/debugger/devtools_resources.gyp
diff --git a/content/browser/debugger/devtools_resources.gyp b/content/browser/debugger/devtools_resources.gyp
index f29be19d5b36ac6ba1e2a50b44946598db196a75..79670d436cf08b8d897a3b27b69698e8637e9831 100644
--- a/content/browser/debugger/devtools_resources.gyp
+++ b/content/browser/debugger/devtools_resources.gyp
@@ -3,12 +3,21 @@
 # found in the LICENSE file.
 
 {
+  'variables': {
+    'conditions': [
+      ['inside_chromium_build==0', {
+        'webkit_src_dir': '../../../../../..',
+      },{
+        'webkit_src_dir': '../../../third_party/WebKit',
+      }],
+    ],
+  },
   'targets': [
     {
       'target_name': 'devtools_resources',
       'type': 'none',
       'dependencies': [
-        '../../../third_party/WebKit/Source/WebKit/chromium/WebKit.gyp:generate_devtools_grd',
+        '<(webkit_src_dir)/Source/WebKit/chromium/WebKit.gyp:generate_devtools_grd',
       ],
       'variables': {
         'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/webkit',