Add a build target for perf_av bot dependencies.

build/all.gyp

Index: build/all.gyp
diff --git a/build/all.gyp b/build/all.gyp
index 20ed72217262bc860ab887aa0be286aa3e764930..dcb918b2cd394e77d36d05509612c0d7baaf155c 100644
--- a/build/all.gyp
+++ b/build/all.gyp
@@ -331,6 +331,14 @@
             }],
           ],
         }, # target_name: chromium_builder_qa
+        {
+          'target_name': 'chromium_builder_perf_av',
+          'type': 'none',
+          'dependencies': [
+            'chromium_builder_qa',  # needed for perf pyauto tests
+            '../webkit/webkit.gyp:pull_in_DumpRenderTree',  # to run layout tests
+          ],
+        },  # target_name: chromium_builder_perf_av
       ],  # targets
     }],
     ['OS=="mac"', {