Add RandomString() and its test, and use it everywhere it makes sense

util/win/exception_handler_server.cc

 // Copyright 2015 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 #include "util/win/exception_handler_server.h"
 
 #include <sddl.h>
 #include <string.h>
 
 #include "base/logging.h"
 #include "base/numerics/safe_conversions.h"
 #include "base/rand_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "minidump/minidump_file_writer.h"
 #include "snapshot/crashpad_info_client_options.h"
 #include "snapshot/win/process_snapshot_win.h"
 #include "util/file/file_writer.h"
+#include "util/misc/random_string.h"
 #include "util/misc/tri_state.h"
 #include "util/misc/uuid.h"
 #include "util/win/get_function.h"
 #include "util/win/handle.h"
 #include "util/win/registration_protocol_win.h"
 #include "util/win/scoped_local_alloc.h"
 #include "util/win/xp_compat.h"
 
 namespace crashpad {
 
@@ skipping 272 matching lines @@
 }
 
 std::wstring ExceptionHandlerServer::CreatePipe() {
   DCHECK(!first_pipe_instance_.is_valid());
 
   int tries = 5;
   std::string pipe_name_base =
       base::StringPrintf("\\\\.\\pipe\\crashpad_%d_", GetCurrentProcessId());
   std::wstring pipe_name;
   do {
-    pipe_name = base::UTF8ToUTF16(pipe_name_base);
-    for (int index = 0; index < 16; ++index) {
-      pipe_name.append(1, static_cast<wchar_t>(base::RandInt('A', 'Z')));
-    }
+    pipe_name = base::UTF8ToUTF16(pipe_name_base + RandomString());
 
     first_pipe_instance_.reset(CreateNamedPipeInstance(pipe_name, true));
 
     // CreateNamedPipe() is documented as setting the error to
     // ERROR_ACCESS_DENIED if FILE_FLAG_FIRST_PIPE_INSTANCE is specified and the
     // pipe name is already in use. However it may set the error to other codes
     // such as ERROR_PIPE_BUSY (if the pipe already exists and has reached its
     // maximum instance count) or ERROR_INVALID_PARAMETER (if the pipe already
     // exists and its attributes differ from those specified to
     // CreateNamedPipe()). Some of these errors may be ambiguous: for example,
@@ skipping 259 matching lines @@
 void __stdcall ExceptionHandlerServer::OnProcessEnd(void* ctx, BOOLEAN) {
   // This function is executed on the thread pool.
   internal::ClientData* client = reinterpret_cast<internal::ClientData*>(ctx);
   base::AutoLock lock(*client->lock());
 
   // Post back to the main thread to have it delete this client record.
   PostQueuedCompletionStatus(client->port(), 0, ULONG_PTR(client), nullptr);
 }
 
 }  // namespace crashpad