First cut at UI for saving net_logs data into a temporary file on

chrome/browser/net/net_log_temp_file.cc

+// Copyright (c) 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/net/net_log_temp_file.h"
+
+#include "base/file_util.h"
+#include "base/values.h"
+#include "chrome/browser/net/chrome_net_log.h"
+#include "chrome/browser/net/net_log_logger.h"
+#include "content/public/browser/browser_thread.h"
+
+using content::BrowserThread;
+
+NetLogTempFile::NetLogTempFile(ChromeNetLog* chrome_net_log)
+    : state_(STATE_UNINITIALIZED),
+      log_filename_(FILE_PATH_LITERAL("chrome-net-export-log.json")),
+      chrome_net_log_(chrome_net_log) {
+}
+
+NetLogTempFile::~NetLogTempFile() {
+  if (net_log_logger_.get())

[mmenke, 2013/01/28 21:51:41]

nit:  .get() not needed (And the preferred for is to leave it off)

[ramant (doing other things), 2013/01/29 04:48:37]

Done.

+    net_log_logger_->StopObserving();
+}
+
+void NetLogTempFile::ProcessCommand(Command command) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  if (!EnsureInit())
+    return;
+
+  switch (command) {
+    case DO_START:
+      StartNetLog();
+      break;
+    case DO_STOP:
+      StopNetLog();
+      break;
+    default:

[mmenke, 2013/01/28 21:51:41]

NOTREACHED()?

[ramant (doing other things), 2013/01/29 04:48:37]

Done.

+      break;
+  }
+}
+
+DictionaryValue* NetLogTempFile::GetState() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  base::DictionaryValue* dict = new base::DictionaryValue;
+
+  ignore_result(EnsureInit());

[mmenke, 2013/01/28 21:51:41]

I don't beloeve ignore_result is needed unless WARN_UNUSED_RESULT is used in the
function declaration.

[ramant (doing other things), 2013/01/29 04:48:37]

Done.

+
+#ifndef NDEBUG
+  dict->SetString("file", log_path_.LossyDisplayName());
+#endif  // NDEBUG
+
+  switch (state_) {
+    case STATE_ALLOW_START:
+      dict->SetString("state", "ALLOW_START");
+      break;
+    case STATE_ALLOW_STOP:
+      dict->SetString("state", "ALLOW_STOP");
+      break;
+    case STATE_ALLOW_START_SEND:
+      dict->SetString("state", "ALLOW_START_SEND");
+      break;
+    default:
+      dict->SetString("state", "UNINITIALIZED");
+      break;
+  }
+  return dict;
+}
+
+bool NetLogTempFile::EnsureInit() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  if (state_ != STATE_UNINITIALIZED)
+    return true;
+
+  if (!GetNetExportLog())
+    return false;
+
+  if (NetExportLogExists())
+    state_ = STATE_ALLOW_START_SEND;
+  else
+    state_ = STATE_ALLOW_START;
+
+  return true;
+}
+
+void NetLogTempFile::StartNetLog() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  if (state_ == STATE_ALLOW_STOP)
+    return;
+
+  DCHECK_NE(state_, STATE_UNINITIALIZED);

[mmenke, 2013/01/28 21:51:41]

nit:  Expected goes first, so this should be:

DCHECK_NE(STATE_UNINITIALIZED, state_);

[ramant (doing other things), 2013/01/29 04:48:37]

Done.

+  DCHECK(!log_path_.empty());
+
+  // Try to make sure we can create the file.
+  // TODO(rtenneti): Find a better for doing the following. Surface some error
+  // to the user if we couldn't create the file.
+  FILE* fp = file_util::OpenFile(log_path_, "w");
+  if (!fp)
+    return;
+  file_util::CloseFile(fp);
+
+  net_log_logger_.reset(new NetLogLogger(log_path_));
+  net_log_logger_->StartObserving(chrome_net_log_);
+  state_ = STATE_ALLOW_STOP;
+}
+
+void NetLogTempFile::StopNetLog() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  if (state_ != STATE_ALLOW_STOP)
+    return;
+
+  net_log_logger_->StopObserving();
+  net_log_logger_.reset();
+  state_ = STATE_ALLOW_START_SEND;
+}
+
+bool NetLogTempFile::GetFilePath(FilePath* path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  if (state_ != STATE_ALLOW_START_SEND)
+    return false;
+
+  if (!NetExportLogExists())
+    return false;
+

[mmenke, 2013/01/28 21:51:41]

optional:  DCHECK(!log_path_.empty());

[ramant (doing other things), 2013/01/29 04:48:37]

Done.

+#if defined(OS_POSIX)
+  // Users, group and others can read, write and traverse.
+  int mode = file_util::FILE_PERMISSION_MASK;
+  file_util::SetPosixFilePermissions(log_path_, mode);
+#endif  // defined(OS_POSIX)
+
+  *path = log_path_;
+  return true;
+}
+
+bool NetLogTempFile::GetNetExportLog() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  FilePath temp_dir;
+  if (!GetNetExportLogDirectory(&temp_dir))
+    return false;
+
+  log_path_ = temp_dir.Append(log_filename_);
+  return true;
+}
+
+bool NetLogTempFile::GetNetExportLogDirectory(FilePath* path) {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));
+  return file_util::GetTempDir(path);
+}
+
+bool NetLogTempFile::NetExportLogExists() {
+  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::FILE_USER_BLOCKING));

[mmenke, 2013/01/28 21:51:41]

DCHECK_NE(STATE_UNINITIALIZED, state_);
DCHECK(!log_path_.empty());

(Alternatively, could just return false if the first isn't true, and then have
the second check).

[ramant (doing other things), 2013/01/29 04:48:37]

Added "DCHECK(!log_path_.empty());".

This function could be called when state_ is STATE_UNINITIALIZED from ensureInit
to determine the state_.

The function could be called when state_ is not STATE_UNINITIALIZED (when state_
is STATE_ALLOW_START_SEND) from GetFilePath().  GetFilePath is called when user
clicks on Send. If the file doesn't exist SendEmail doesn't attach the file and
doesn't send email (if user manually deletes the file from the storage area. Not
sure if that is possible on mobile device).

Thus didn't add the first DCHECK.

+  return file_util::PathExists(log_path_);
+}