drive: Switch Drive mount path to per-profile one.

chrome/browser/chromeos/drive/file_system_util.h

Index: chrome/browser/chromeos/drive/file_system_util.h
diff --git a/chrome/browser/chromeos/drive/file_system_util.h b/chrome/browser/chromeos/drive/file_system_util.h
index 2b3ead4c13714ca587f132dc0cc368006ae44fcd..e6b56b9efba857e0ed9d32986a87bad0ba9e58f9 100644
--- a/chrome/browser/chromeos/drive/file_system_util.h
+++ b/chrome/browser/chromeos/drive/file_system_util.h
@@ -59,9 +59,8 @@ const base::FilePath& GetDriveGrandRootPath();
 // Returns the path of the directory representing "My Drive".
 const base::FilePath& GetDriveMyDriveRootPath();
 
-// Returns the Drive mount point path, which looks like
-// "/special/drive-<unique-id-of-profile>".
-const base::FilePath& GetDriveMountPointPath(Profile* profile);
+// Returns the Drive mount point path, which looks like "/special/drive-<hash>".
+base::FilePath GetDriveMountPointPath(Profile* profile);
 
 // Returns the FileSystem for the |profile|. If not available (not mounted
 // or disabled), returns NULL.
@@ -102,6 +101,11 @@ bool IsUnderDriveMountPoint(const base::FilePath& path);
 // Examples: ExtractDrivePath("/special/drive-xxx/foo.txt") => "drive/foo.txt"
 base::FilePath ExtractDrivePath(const base::FilePath& path);
 
+// Extracts |profile| from the given paths located under
+// GetDriveMountPointPath(profile). Returns NULL if it does not correspond to
+// a valid mount point path. Must be called from UI thread.
+Profile* ExtractProfileFromPath(const base::FilePath& path);
+
 // Extracts the Drive path (e.g., "drive/foo.txt") from the filesystem URL.
 // Returns an empty path if |url| does not point under Drive mount point.
 base::FilePath ExtractDrivePathFromFileSystemUrl(