Rename the shared impl files.

ppapi/shared_impl/ppb_instance_shared.cc

Index: ppapi/shared_impl/ppb_instance_shared.cc
diff --git a/ppapi/shared_impl/instance_impl.cc b/ppapi/shared_impl/ppb_instance_shared.cc
similarity index 76%
rename from ppapi/shared_impl/instance_impl.cc
rename to ppapi/shared_impl/ppb_instance_shared.cc
index ad1674aa8d78cee85db01fc1ca7087c4355d6ce3..a2416cefaa9e2a47bf52b51b08eba85115ef8538 100644
--- a/ppapi/shared_impl/instance_impl.cc
+++ b/ppapi/shared_impl/ppb_instance_shared.cc
@@ -2,18 +2,19 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "ppapi/shared_impl/instance_impl.h"
+#include "ppapi/shared_impl/ppb_instance_shared.h"
 
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_input_event.h"
 
 namespace ppapi {
 
-InstanceImpl::~InstanceImpl() {
+PPB_Instance_Shared::~PPB_Instance_Shared() {
 }
 
-int32_t InstanceImpl::ValidateRequestInputEvents(bool is_filtering,
-                                                 uint32_t event_classes) {
+int32_t PPB_Instance_Shared::ValidateRequestInputEvents(
+    bool is_filtering,
+    uint32_t event_classes) {
   // See if any bits are set we don't know about.
   if (event_classes &
       ~static_cast<uint32_t>(PP_INPUTEVENT_CLASS_MOUSE |