The return value of ClosePlatformFile() was reversed in r59041. Most

calls to ClosePlatformFile() ignore the return value, but there are
two calls that do use it:

1. webkit/glue/webfileutilities_impl.cc, closeFile() method: i talked
to jianli who changed that method most recently, and he said he
prefers the handle to be reset to base::kInvalidPlatformFileValue if
ClosePlatformFile() succeeded, so no change is needed to that code.

2. webkit/database/database_tracker.cc, CloseIncognitoFileHandle():
this code needs to be updated.

TEST=WebSQLDBs don't crash in incognito mode.
BUG=56237

Review URL: http://codereview.chromium.org/3387018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@60685 0039d316-1c4b-4281-b951-d872f2087c98

base/platform_file.h

@@ -97,7 +97,7 @@ PlatformFile CreatePlatformFile(const std::wstring& name,
                                 int flags,
                                 bool* created);
 
-// Closes a file handle
+// Closes a file handle. Returns |true| on success and |false| otherwise.
 bool ClosePlatformFile(PlatformFile file);
 
 // Reads the given number of bytes (or until EOF is reached) starting with the

webkit/database/database_tracker.cc

@@ -629,7 +629,7 @@ bool DatabaseTracker::CloseIncognitoFileHandle(const string16& vfs_file_name) {
   bool handle_closed = false;
   FileHandlesMap::iterator it = incognito_file_handles_.find(vfs_file_name);
   if (it != incognito_file_handles_.end()) {
-    handle_closed = !base::ClosePlatformFile(it->second);
+    handle_closed = base::ClosePlatformFile(it->second);
     if (handle_closed)
       incognito_file_handles_.erase(it);
   }