Add MinidumpCrashpadInfoWriter::InitializeFromSnapshot() and its test

minidump/minidump_crashpad_info_writer.cc

Index: minidump/minidump_crashpad_info_writer.cc
diff --git a/minidump/minidump_crashpad_info_writer.cc b/minidump/minidump_crashpad_info_writer.cc
index 22be59773c83811d914dab003d2fb1dc2739005b..b77796eabe515ce87cd490d8f0b637333e1fe24a 100644
--- a/minidump/minidump_crashpad_info_writer.cc
+++ b/minidump/minidump_crashpad_info_writer.cc
@@ -16,6 +16,7 @@
 
 #include "base/logging.h"
 #include "minidump/minidump_module_crashpad_info_writer.h"
+#include "snapshot/process_snapshot.h"
 #include "util/file/file_writer.h"
 
 namespace crashpad {
@@ -28,6 +29,19 @@ MinidumpCrashpadInfoWriter::MinidumpCrashpadInfoWriter()
 MinidumpCrashpadInfoWriter::~MinidumpCrashpadInfoWriter() {
 }
 
+void MinidumpCrashpadInfoWriter::InitializeFromSnapshot(
+    const ProcessSnapshot* process_snapshot) {
+  DCHECK_EQ(state(), kStateMutable);
+  DCHECK(!module_list_);
+
+  auto modules = make_scoped_ptr(new MinidumpModuleCrashpadInfoListWriter());
+  modules->InitializeFromSnapshot(process_snapshot->Modules());
+
+  if (modules->IsUseful()) {
+    SetModuleList(modules.Pass());
+  }
+}
+
 void MinidumpCrashpadInfoWriter::SetModuleList(
     scoped_ptr<MinidumpModuleCrashpadInfoListWriter> module_list) {
   DCHECK_EQ(state(), kStateMutable);
@@ -77,4 +91,8 @@ MinidumpStreamType MinidumpCrashpadInfoWriter::StreamType() const {
   return kMinidumpStreamTypeCrashpadInfo;
 }
 
+bool MinidumpCrashpadInfoWriter::IsUseful() const {
+  return module_list_;
+}
+
 }  // namespace crashpad