Add a gyp flag to allow removing dependency on ppapi.

content/content_renderer.gypi

Index: content/content_renderer.gypi
diff --git a/content/content_renderer.gypi b/content/content_renderer.gypi
index a0dde73f3378cf96a9bae50a9b611e1672896deb..d593e8af8d95c1231f4ef046e0e0b19ec4f5da91 100644
--- a/content/content_renderer.gypi
+++ b/content/content_renderer.gypi
@@ -6,9 +6,6 @@
   'dependencies': [
     '../jingle/jingle.gyp:jingle_glue',
     '../net/net.gyp:net',
-    '../ppapi/ppapi_internal.gyp:ppapi_host',
-    '../ppapi/ppapi_internal.gyp:ppapi_proxy',
-    '../ppapi/ppapi_internal.gyp:ppapi_shared',
     '../skia/skia.gyp:skia',
     '../third_party/hyphen/hyphen.gyp:hyphen',
     '../third_party/icu/icu.gyp:icuuc',
@@ -208,6 +205,8 @@
     'renderer/pepper/renderer_ppapi_host_impl.h',
     'renderer/plugin_channel_host.cc',
     'renderer/plugin_channel_host.h',
+    'renderer/plugin_delegate_helper.cc',
+    'renderer/plugin_delegate_helper.h',
     'renderer/browser_plugin/browser_plugin.cc',
     'renderer/browser_plugin/browser_plugin.h',
     'renderer/browser_plugin/browser_plugin_backing_store.h',
@@ -365,6 +364,17 @@
         'renderer/p2p/socket_dispatcher.h',
       ],
     }],
+    ['enable_ppapi==1', {
+      'dependencies': [
+        '../ppapi/ppapi_internal.gyp:ppapi_host',
+        '../ppapi/ppapi_internal.gyp:ppapi_proxy',
+        '../ppapi/ppapi_internal.gyp:ppapi_shared',
+      ],
+    }, {  # enable_ppapi==0
+      'sources/': [
+        ['exclude', '^renderer/pepper/'],
+      ],
+    }],
     ['java_bridge==1', {
       'defines': [
         'ENABLE_JAVA_BRIDGE',