Pepper: Make sure 'out' params are initialized for all code paths.

ppapi/proxy/ppb_image_data_proxy.cc

Index: ppapi/proxy/ppb_image_data_proxy.cc
diff --git a/ppapi/proxy/ppb_image_data_proxy.cc b/ppapi/proxy/ppb_image_data_proxy.cc
index 51751668f228dd9fef77218feabfcf55010eef47..e509076a90903def9de6f08c349eb37f6f2b0a40 100644
--- a/ppapi/proxy/ppb_image_data_proxy.cc
+++ b/ppapi/proxy/ppb_image_data_proxy.cc
@@ -494,9 +494,7 @@ PP_Resource PPB_ImageData_Proxy::CreateProxyResource(
   }
 
   HostResource result;
-  // Initialize desc so we don't send unitialized memory over IPC.
-  // https://crbug.com/391023.
-  PP_ImageDataDesc desc = {};
+  PP_ImageDataDesc desc;
   switch (type) {
     case PPB_ImageData_Shared::SIMPLE: {
       ppapi::proxy::SerializedHandle image_handle_wrapper;
@@ -622,6 +620,9 @@ void PPB_ImageData_Proxy::OnHostMsgCreatePlatform(
     HostResource* result,
     PP_ImageDataDesc* desc,
     ImageHandle* result_image_handle) {
+  // Clear |desc| so we don't send unitialized memory to the plugin.
+  // https://crbug.com/391023.
+  memset(desc, 0, sizeof(*desc));

[dmichael (off chromium), 2014/07/11 15:22:25]

*desc = PP_ImageDataDesc();
?

[bbudge, 2014/07/11 15:23:40]

David, the reason I've gone back to memset is to ensure that padding bytes are
also cleared. In this case there are none, but this seems like a good pattern to
set.

[dmichael (off chromium), 2014/07/11 15:51:52]

Okay, that makes sense. still lgtm

[bbudge, 2014/07/11 17:01:55]

Sorry for churn, switching back to *desc = PP_ImageDataDesc() for clarity. This
isn't the right place to try to fix information leaks through padding.

   IPC::PlatformFileForTransit image_handle;
   uint32_t byte_count;
   PP_Resource resource =
@@ -647,6 +648,9 @@ void PPB_ImageData_Proxy::OnHostMsgCreateSimple(
     HostResource* result,
     PP_ImageDataDesc* desc,
     ppapi::proxy::SerializedHandle* result_image_handle) {
+  // Clear |desc| so we don't send unitialized memory to the plugin.
+  // https://crbug.com/391023.
+  memset(desc, 0, sizeof(*desc));
   IPC::PlatformFileForTransit image_handle;
   uint32_t byte_count;
   PP_Resource resource =