Put the Pepper stuff in the content namespace.

content/renderer/pepper/pepper_broker_impl.h

Index: content/renderer/pepper/pepper_broker_impl.h
diff --git a/content/renderer/pepper/pepper_broker_impl.h b/content/renderer/pepper/pepper_broker_impl.h
index 70c6f23762cd4f0b3aeb1f3cf9e5094ae1064e31..cbed850e836e8cc5f2fb1348a769e2d15727dc2f 100644
--- a/content/renderer/pepper/pepper_broker_impl.h
+++ b/content/renderer/pepper/pepper_broker_impl.h
@@ -11,8 +11,6 @@
 #include "webkit/plugins/ppapi/plugin_delegate.h"
 #include "webkit/plugins/ppapi/ppb_broker_impl.h"
 
-class PepperPluginDelegateImpl;
-
 namespace IPC {
 struct ChannelHandle;
 }
@@ -29,6 +27,10 @@ class PluginModule;
 }
 }
 
+namespace content {
+
+class PepperPluginDelegateImpl;
+
 // This object is NOT thread-safe.
 class CONTENT_EXPORT PepperBrokerDispatcherWrapper {
  public:
@@ -90,4 +92,6 @@ class PepperBrokerImpl : public webkit::ppapi::PluginDelegate::Broker,
   DISALLOW_COPY_AND_ASSIGN(PepperBrokerImpl);
 };
 
+}  // namespace content
+
 #endif  // CONTENT_RENDERER_PEPPER_PEPPER_BROKER_IMPL_H_