Add new method OverrideAndCreateIfNeeded to PathService.

This is prerequisite for adding support for running chrome on network
shared location

BUG=120388
TEST=base_unittests:PathServiceTest.Override

Review URL: https://chromiumcodereview.appspot.com/10388027

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136017 0039d316-1c4b-4281-b951-d872f2087c98

3 files changed, 52 insertions, 9 deletions

diff --git a/base/path_service.cc b/base/path_service.cc
index 46f394c..a3b882c 100644
--- a/base/path_service.cc
+++ b/base/path_service.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -222,18 +222,29 @@ bool PathService::Get(int key, FilePath* result) {
 }
 
 bool PathService::Override(int key, const FilePath& path) {
+  // Just call the full function with true for the value of |create|.
+  return OverrideAndCreateIfNeeded(key, path, true);
+}
+
+bool PathService::OverrideAndCreateIfNeeded(int key,
+                                            const FilePath& path,
+                                            bool create) {
   PathData* path_data = GetPathData();
   DCHECK(path_data);
   DCHECK_GT(key, base::DIR_CURRENT) << "invalid path key";
 
   FilePath file_path = path;
 
-  // Make sure the directory exists. We need to do this before we translate
-  // this to the absolute path because on POSIX, AbsolutePath fails if called
-  // on a non-existent path.
-  if (!file_util::PathExists(file_path) &&
-      !file_util::CreateDirectory(file_path))
-    return false;
+  // For some locations this will fail if called from inside the sandbox there-
+  // fore we protect this call with a flag.
+  if (create) {
+    // Make sure the directory exists. We need to do this before we translate
+    // this to the absolute path because on POSIX, AbsolutePath fails if called
+    // on a non-existent path.
+    if (!file_util::PathExists(file_path) &&
+        !file_util::CreateDirectory(file_path))
+      return false;
+  }
 
   // We need to have an absolute path, as extensions and plugins don't like
   // relative paths, and will gladly crash the browser in CHECK()s if they get a
diff --git a/base/path_service.h b/base/path_service.h
index 4b29738..03e4b44 100644
--- a/base/path_service.h
+++ b/base/path_service.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -40,6 +40,13 @@ class BASE_EXPORT PathService {
   // over the lifetime of the app, so this method should be used with caution.
   static bool Override(int key, const FilePath& path);
 
+  // This function does the same as PathService::Override but it takes an extra
+  // parameter |create| which guides whether the directory to be overriden must
+  // be created in case it doesn't exist already.
+  static bool OverrideAndCreateIfNeeded(int key,
+                                        const FilePath& path,
+                                        bool create);
+
   // To extend the set of supported keys, you can register a path provider,
   // which is just a function mirroring PathService::Get.  The ProviderFunc
   // returns false if it cannot provide a non-empty path for the given key.
diff --git a/base/path_service_unittest.cc b/base/path_service_unittest.cc
index ec9cf28..294f8d8 100644
--- a/base/path_service_unittest.cc
+++ b/base/path_service_unittest.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Copyright (c) 2012 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.
 
@@ -7,6 +7,7 @@
 #include "base/basictypes.h"
 #include "base/file_util.h"
 #include "base/file_path.h"
+#include "base/scoped_temp_dir.h"
 #if defined(OS_WIN)
 #include "base/win/windows_version.h"
 #endif
@@ -74,3 +75,27 @@ TEST_F(PathServiceTest, Get) {
   }
 #endif
 }
+
+// test that all versions of the Override function of PathService do what they
+// are supposed to do.
+TEST_F(PathServiceTest, Override) {
+  int my_special_key = 666;
+  ScopedTempDir temp_dir;
+  ASSERT_TRUE(temp_dir.CreateUniqueTempDir());
+  FilePath fake_cache_dir(temp_dir.path().AppendASCII("cache"));
+  // PathService::Override should always create the path provided if it doesn't
+  // exist.
+  EXPECT_TRUE(PathService::Override(my_special_key, fake_cache_dir));
+  EXPECT_TRUE(file_util::PathExists(fake_cache_dir));
+
+  FilePath fake_cache_dir2(temp_dir.path().AppendASCII("cache2"));
+  // PathService::OverrideAndCreateIfNeeded should obey the |create| parameter.
+  PathService::OverrideAndCreateIfNeeded(my_special_key,
+                                         fake_cache_dir2,
+                                         false);
+  EXPECT_FALSE(file_util::PathExists(fake_cache_dir2));
+  EXPECT_TRUE(PathService::OverrideAndCreateIfNeeded(my_special_key,
+                                                     fake_cache_dir2,
+                                                     true));
+  EXPECT_TRUE(file_util::PathExists(fake_cache_dir2));
+}