base: TemporaryDir add DoNotRemove() method

Recursively delete all contents in a temporary directory in the
destructor.  If the caller wants the contents preserved, then
call DoNotRemove().

Test: compile
Bug: 119313545
Change-Id: I3601c06334920055a60dd3074b249824f4d6f510

base/file.cpp

@@ -134,6 +134,8 @@ TemporaryDir::TemporaryDir() {
 }
 
 TemporaryDir::~TemporaryDir() {
+  if (!remove_dir_and_contents_) return;
+
   auto callback = [](const char* child, const struct stat*, int file_type, struct FTW*) -> int {
     switch (file_type) {
       case FTW_D:

base/include/android-base/file.h

@@ -61,12 +61,16 @@ class TemporaryDir {
  public:
   TemporaryDir();
   ~TemporaryDir();
+  // Don't remove the temporary dir in the destructor.
+  void DoNotRemove() { remove_dir_and_contents_ = false; }
 
   char path[1024];
 
  private:
   bool init(const std::string& tmp_dir);
 
+  bool remove_dir_and_contents_ = true;
+
   DISALLOW_COPY_AND_ASSIGN(TemporaryDir);
 };