Sandbox the component updater's patcher utility process.

courgette/courgette.h

Index: courgette/courgette.h
diff --git a/courgette/courgette.h b/courgette/courgette.h
index 5f3dbb8367a81ba5f86f85ccd92399a3f7d7e9ac..0e289441165e7630a8f69c0163fd0dbb114225a1 100644
--- a/courgette/courgette.h
+++ b/courgette/courgette.h
@@ -9,6 +9,10 @@
 
 #include "base/files/file_path.h"
 
+namespace base {
+class File;

[huangs, 2016/12/06 18:23:22]

Same comment as in bsdiff.h: Please
- Remove the forward declaration.
- #include "base/files/file.h"

[waffles, 2016/12/06 19:18:45]

Done, thanks; this was leftover from an intermediate form of the code.

+}  // namespace base
+
 namespace courgette {
 
 // Status codes for Courgette APIs.
@@ -83,6 +87,15 @@ Status ApplyEnsemblePatch(const base::FilePath::CharType* old_file_name,
                           const base::FilePath::CharType* patch_file_name,
                           const base::FilePath::CharType* new_file_name);
 
+// Applies the patch in |patch_file| to the bytes in |old_file| and writes the

[huangs, 2016/12/06 18:30:32]

Please move this between the SourceStream* version and the FielPath::CharType*
version, same in .cc file.

[waffles, 2016/12/06 19:18:45]

Done. Curious: What's the rationale here?

[huangs, 2016/12/06 19:40:07]

Ah, symmetry: We have A() calling B() alling C(), I'd prefer call direction to
be upwards.

+// transformed ensemble to |new_file|.
+// Returns C_OK unless something went wrong.
+// This function first validates that the patch file has a proper header, so the
+// function can be used to 'try' a patch.
+Status ApplyEnsemblePatch(base::File old_file,
+                          base::File patch_file,
+                          base::File new_file);
+
 // Generates a patch that will transform the bytes in |old| into the bytes in
 // |target|.
 // Returns C_OK unless something when wrong (unexpected).