Define iTunes location for media galleries tests.

chrome/browser/media_galleries/media_galleries_test_util.cc

Index: chrome/browser/media_galleries/media_galleries_test_util.cc
diff --git a/chrome/browser/media_galleries/media_galleries_test_util.cc b/chrome/browser/media_galleries/media_galleries_test_util.cc
index 0f01e1e76a18f53177c00b25c3215b3dfe008f79..1c7da21578f30e7084a55b35ed8ef4e4e35b1623 100644
--- a/chrome/browser/media_galleries/media_galleries_test_util.cc
+++ b/chrome/browser/media_galleries/media_galleries_test_util.cc
@@ -18,6 +18,12 @@
 #include "chrome/common/extensions/extension_manifest_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
+#if defined(OS_MACOSX)
+#include "base/mac/foundation_util.h"
+#include "chrome/browser/media_galleries/fileapi/itunes_finder_mac.h"
+#include "chrome/browser/policy/preferences_mock_mac.h"
+#endif
+
 namespace chrome {
 
 scoped_refptr<extensions::Extension> AddMediaGalleriesApp(
@@ -75,6 +81,10 @@ EnsureMediaDirectoriesExists::EnsureMediaDirectoriesExists()
 }
 
 EnsureMediaDirectoriesExists::~EnsureMediaDirectoriesExists() {
+#if defined(OS_MACOSX)
+  // Free the MockPreferences object.
+  itunes::ITunesFinderMac::SetMacPreferencesForTesting(NULL);
+#endif
 }
 
 void EnsureMediaDirectoriesExists::Init() {
@@ -84,11 +94,19 @@ void EnsureMediaDirectoriesExists::Init() {
 
   ASSERT_TRUE(fake_dir_.CreateUniqueTempDir());
 
-#if defined(OS_WIN) || defined(OS_MACOSX)
+#if defined(OS_WIN)
   // This is to make sure the tests don't think iTunes is installed (unless
   // we control it specifically).
   appdir_override_.reset(new base::ScopedPathOverride(
       base::DIR_APP_DATA, fake_dir_.path().AppendASCII("itunes")));
+#elif defined(OS_MACOSX)
+  MockPreferences* prefs = new MockPreferences;
+  NSString* path = base::mac::FilePathToNSString(
+      fake_dir_.path().AppendASCII("itunes"));
+  CFArrayRef array = CFArrayCreate(NULL, (const void **)(&path), 1,
+                                   &kCFTypeArrayCallBacks);

[Lei Zhang, 2013/08/13 20:02:34]

I have no idea if this is right. Care to ask someone who knows mac code?

+  prefs->AddTestItem(CFSTR("iTunesRecentDatabasePaths"), array, false);

[Lei Zhang, 2013/08/13 20:02:34]

Can we make "iTunesRecentDatabasePaths" a const?

+  itunes::ITunesFinderMac::SetMacPreferencesForTesting(prefs);
 #endif
 
   music_override_.reset(new base::ScopedPathOverride(