Harden CommandBufferProxyImpl

content/common/gpu/client/command_buffer_proxy_impl.cc

Index: content/common/gpu/client/command_buffer_proxy_impl.cc
diff --git a/content/common/gpu/client/command_buffer_proxy_impl.cc b/content/common/gpu/client/command_buffer_proxy_impl.cc
index a8b4ba0fe0b34abb87d65a56fecf28e532600773..9176919e2e0ac86ca9071d314402df7b6fd3cf1d 100644
--- a/content/common/gpu/client/command_buffer_proxy_impl.cc
+++ b/content/common/gpu/client/command_buffer_proxy_impl.cc
@@ -83,7 +83,10 @@ bool CommandBufferProxyImpl::OnMessageReceived(const IPC::Message& message) {
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
-  DCHECK(handled);
+  if (!handled) {
+    DLOG(ERROR) << "Gpu process sent invalid message.";
+    InvalidGpuMessage();
+  }
   return handled;
 }
 
@@ -149,7 +152,11 @@ void CommandBufferProxyImpl::RemoveDeletionObserver(
 
 void CommandBufferProxyImpl::OnSignalAck(uint32_t id) {
   SignalTaskMap::iterator it = signal_tasks_.find(id);
-  DCHECK(it != signal_tasks_.end());
+  if (it == signal_tasks_.end()) {
+    DLOG(ERROR) << "Gpu process sent invalid SignalAck.";
+    InvalidGpuMessage();
+    return;
+  }
   base::Closure callback = it->second;
   signal_tasks_.erase(it);
   callback.Run();
@@ -304,8 +311,11 @@ void CommandBufferProxyImpl::WaitForTokenInRange(int32_t start, int32_t end) {
             route_id_, start, end, &state)))
       OnUpdateState(state);
   }
-  DCHECK(InRange(start, end, last_state_.token) ||
-         last_state_.error != gpu::error::kNoError);
+  if (!InRange(start, end, last_state_.token) &&
+      last_state_.error == gpu::error::kNoError) {
+    DLOG(ERROR) << "GPU state invalid after WaitForTokenInRange.";
+    InvalidGpuMessage();
+  }
 }
 
 void CommandBufferProxyImpl::WaitForGetOffsetInRange(int32_t start,
@@ -325,8 +335,11 @@ void CommandBufferProxyImpl::WaitForGetOffsetInRange(int32_t start,
             route_id_, start, end, &state)))
       OnUpdateState(state);
   }
-  DCHECK(InRange(start, end, last_state_.get_offset) ||
-         last_state_.error != gpu::error::kNoError);
+  if (!InRange(start, end, last_state_.get_offset) &&
+      last_state_.error == gpu::error::kNoError) {
+    DLOG(ERROR) << "GPU state invalid after WaitForGetOffsetInRange.";
+    InvalidGpuMessage();
+  }
 }
 
 void CommandBufferProxyImpl::SetGetBuffer(int32_t shm_id) {
@@ -778,4 +791,9 @@ void CommandBufferProxyImpl::OnUpdateVSyncParameters(base::TimeTicks timebase,
     update_vsync_parameters_completion_callback_.Run(timebase, interval);
 }
 
+void CommandBufferProxyImpl::InvalidGpuMessage() {
+  LOG(ERROR) << "Received invalid message or reply from the GPU process.";
+  OnDestroyed(gpu::error::kInvalidGpuMessage, gpu::error::kLostContext);
+}
+
 }  // namespace content