Use UtilityProcessHost to patch files.

chrome/common/chrome_utility_messages.h

Index: chrome/common/chrome_utility_messages.h
diff --git a/chrome/common/chrome_utility_messages.h b/chrome/common/chrome_utility_messages.h
index 1f76e34c3a00d5f0ae26090c18ab919c645415c7..c8c4d5c5a3d5842801576b2e65bb500fb73bc2e0 100644
--- a/chrome/common/chrome_utility_messages.h
+++ b/chrome/common/chrome_utility_messages.h
@@ -169,6 +169,22 @@ IPC_MESSAGE_CONTROL1(ChromeUtilityMsg_ParseJSON,
 IPC_MESSAGE_CONTROL1(ChromeUtilityMsg_GetPrinterCapsAndDefaults,
                      std::string /* printer name */)
 
+// Tell the utility process to patch the given |input_file| using |patch_file|

[Sorin Jianu, 2014/02/03 20:57:57]

Tells

[waffles, 2014/02/07 01:00:59]

Done.

+// and place the output in |output_file|. The patch should use the bsdiff
+// algorithm (Courgette's version).
+IPC_MESSAGE_CONTROL3(ChromeUtilityMsg_PatchFileBsdiff,
+                     base::FilePath /* input_file */,
+                     base::FilePath /* patch_file */,
+                     base::FilePath /* output_file */)
+
+// Tell the utility process to patch the given |input_file| using |patch_file|
+// and place the output in |output_file|. The patch should use the Courgette
+// algorithm.
+IPC_MESSAGE_CONTROL3(ChromeUtilityMsg_PatchFileCourgette,
+                     base::FilePath /* input_file */,
+                     base::FilePath /* patch_file */,
+                     base::FilePath /* output_file */)
+
 #if defined(OS_CHROMEOS)
 // Tell the utility process to create a zip file on the given list of files.
 IPC_MESSAGE_CONTROL3(ChromeUtilityMsg_CreateZipFile,
@@ -319,6 +335,13 @@ IPC_MESSAGE_CONTROL2(ChromeUtilityHostMsg_GetPrinterCapsAndDefaults_Succeeded,
                      printing::PrinterCapsAndDefaults)
 #endif
 
+// Reply when a file has been patched successfully.
+IPC_MESSAGE_CONTROL0(ChromeUtilityHostMsg_PatchFile_Succeeded)
+
+// Reply when patching a file failed.
+IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_PatchFile_Failed,
+                     int /* error code */)
+
 // Reply when the utility process has failed to obtain the printer
 // capabilities and defaults.
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_GetPrinterCapsAndDefaults_Failed,