gpu: Generate mailboxes on client side

gpu/command_buffer/service/gles2_cmd_decoder.cc

Index: gpu/command_buffer/service/gles2_cmd_decoder.cc
diff --git a/gpu/command_buffer/service/gles2_cmd_decoder.cc b/gpu/command_buffer/service/gles2_cmd_decoder.cc
index 414ecc6adc5da22b004695dc2b8a9af3831d540e..ffa66ed346331407b83933eab49fcf9a51cc616c 100644
--- a/gpu/command_buffer/service/gles2_cmd_decoder.cc
+++ b/gpu/command_buffer/service/gles2_cmd_decoder.cc
@@ -10005,10 +10005,15 @@ error::Error GLES2DecoderImpl::HandleGenMailboxCHROMIUM(
 }
 
 void GLES2DecoderImpl::DoProduceTextureCHROMIUM(GLenum target,
-                                                const GLbyte* mailbox) {
+                                                const GLbyte* data) {
   TRACE_EVENT2("gpu", "GLES2DecoderImpl::DoProduceTextureCHROMIUM",
       "context", logger_.GetLogPrefix(),
-      "mailbox[0]", static_cast<unsigned char>(mailbox[0]));
+      "mailbox[0]", static_cast<unsigned char>(data[0]));
+
+  const Mailbox& mailbox = *reinterpret_cast<const Mailbox*>(data);
+  DLOG_IF(ERROR, !mailbox.Verify()) << "ProduceTextureCHROMIUM was passed a "
+                                       "mailbox that was not generated by "
+                                       "GenMailboxCHROMIUM.";
 
   TextureRef* texture_ref = texture_manager()->GetTextureInfoForTarget(
       &state_, target);
@@ -10027,17 +10032,18 @@ void GLES2DecoderImpl::DoProduceTextureCHROMIUM(GLenum target,
     return;
   }
 
-  group_->mailbox_manager()->ProduceTexture(
-      target,
-      *reinterpret_cast<const Mailbox*>(mailbox),
-      produced);
+  group_->mailbox_manager()->ProduceTexture(target, mailbox, produced);
 }
 
 void GLES2DecoderImpl::DoConsumeTextureCHROMIUM(GLenum target,
-                                                const GLbyte* mailbox) {
+                                                const GLbyte* data) {
   TRACE_EVENT2("gpu", "GLES2DecoderImpl::DoConsumeTextureCHROMIUM",
       "context", logger_.GetLogPrefix(),
-      "mailbox[0]", static_cast<unsigned char>(mailbox[0]));
+      "mailbox[0]", static_cast<unsigned char>(data[0]));
+  const Mailbox& mailbox = *reinterpret_cast<const Mailbox*>(data);
+  DLOG_IF(ERROR, !mailbox.Verify()) << "ConsumeTextureCHROMIUM was passed a "
+                                       "mailbox that was not generated by "
+                                       "GenMailboxCHROMIUM.";
 
   scoped_refptr<TextureRef> texture_ref =
       texture_manager()->GetTextureInfoForTargetUnlessDefault(&state_, target);
@@ -10054,10 +10060,7 @@ void GLES2DecoderImpl::DoConsumeTextureCHROMIUM(GLenum target,
         "glConsumeTextureCHROMIUM", "unknown texture for target");
     return;
   }
-  Texture* texture =
-      group_->mailbox_manager()->ConsumeTexture(
-      target,
-      *reinterpret_cast<const Mailbox*>(mailbox));
+  Texture* texture = group_->mailbox_manager()->ConsumeTexture(target, mailbox);
   if (!texture) {
     LOCAL_SET_GL_ERROR(
         GL_INVALID_OPERATION,