Update the child process security policy to use explicit permission grants.

content/public/browser/child_process_security_policy.h

Index: content/public/browser/child_process_security_policy.h
diff --git a/content/public/browser/child_process_security_policy.h b/content/public/browser/child_process_security_policy.h
index 58d89a2f43a98d24ecea0032ced8e41478f6601d..b17265c1484e686a8d1db31f097c55bd8af1d2f2 100644
--- a/content/public/browser/child_process_security_policy.h
+++ b/content/public/browser/child_process_security_policy.h
@@ -40,12 +40,6 @@ class ChildProcessSecurityPolicy {
   // Returns true iff |scheme| has been registered as a web-safe scheme.
   virtual bool IsWebSafeScheme(const std::string& scheme) = 0;
 
-  // Grants certain permissions to a file. |permissions| must be a bit-set of
-  // base::PlatformFileFlags.
-  virtual void GrantPermissionsForFile(int child_id,
-                                       const base::FilePath& file,
-                                       int permissions) = 0;
-
   // Before servicing a child process's request to upload a file to the web, the
   // browser should call this method to determine whether the process has the
   // capability to upload the requested file.
@@ -53,9 +47,17 @@ class ChildProcessSecurityPolicy {
 
   // Whenever the user picks a file from a <input type="file"> element, the
   // browser should call this function to grant the child process the capability
-  // to upload the file to the web.
+  // to upload the file to the web. Grants FILE_PERMISSION_READ_ONLY.
   virtual void GrantReadFile(int child_id, const base::FilePath& file) = 0;
 
+  // This permission grants creation, read, and full write access to a file,

[Tom Sepez, 2013/07/09 18:52:50]

nit: maybe this should be called GrantCreateReadWriteFile.

[Greg Billock, 2013/07/09 21:09:50]

Done.

+  // including attributes.
+  virtual void GrantReadWriteFile(int child_id, const base::FilePath& file) = 0;
+
+  // This permission grants creation and write access to a file.
+  virtual void GrantCreateWriteFile(int child_id,
+                                    const base::FilePath& file) = 0;
+
   // Grants read access permission to the given isolated file system
   // identified by |filesystem_id|. An isolated file system can be
   // created for a set of native files/directories (like dropped files)