Avoid Polling Dawn When Possible

When Tick() returns false, it means there is no need to call tick
further. This commit changes chromium to only call tick when there
is polling work to be done.

Bug: dawn:119
Bug: chromium:940985
Change-Id: I792837b83f4d0da1d478e3876c9a2af8b1505c2c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2485037
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Austin Eng <enga@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826740}

gpu/command_buffer/service/webgpu_decoder_impl.cc

@@ -145,6 +145,7 @@ class DawnDeviceAndWireServer {
   ~DawnDeviceAndWireServer();
 
   WGPUDevice GetWGPUDevice() const;
+  bool HasPollingWork() const;
   void PerformPollingWork();
   error::Error HandleDawnCommands(const volatile char* dawn_commands,
                                   size_t size);
@@ -176,6 +177,8 @@ class DawnDeviceAndWireServer {
   base::flat_map<std::tuple<uint32_t, uint32_t>,
                  std::unique_ptr<SharedImageRepresentationAndAccess>>
       associated_shared_image_map_;
+
+  bool has_polling_work_ = false;
 };
 
 DawnDeviceAndWireServer::DawnDeviceAndWireServer(
@@ -215,7 +218,7 @@ WGPUDevice DawnDeviceAndWireServer::GetWGPUDevice() const {
 }
 
 void DawnDeviceAndWireServer::PerformPollingWork() {
-  dawn_procs_.deviceTick(wgpu_device_);
+  has_polling_work_ = dawn_native::DeviceTick(wgpu_device_);
   wire_serializer_->Flush();
 }
 
@@ -226,6 +229,7 @@ error::Error DawnDeviceAndWireServer::HandleDawnCommands(
     NOTREACHED();
     return error::kLostContext;
   }
+  has_polling_work_ = dawn_native::DeviceTick(wgpu_device_);
   wire_serializer_->Flush();
   return error::kNoError;
 }
@@ -305,6 +309,10 @@ error::Error DawnDeviceAndWireServer::DissociateMailbox(
   return error::kNoError;
 }
 
+bool DawnDeviceAndWireServer::HasPollingWork() const {
+  return has_polling_work_;
+}
+
 }  // namespace
 
 class WebGPUDecoderImpl final : public WebGPUDecoder {
@@ -383,9 +391,14 @@ class WebGPUDecoderImpl final : public WebGPUDecoder {
   bool HasMoreIdleWork() const override { return false; }
   void PerformIdleWork() override {}
 
-  // TODO(crbug.com/940985): Optimize so that this only returns true when
-  // deviceTick is needed.
-  bool HasPollingWork() const override { return true; }
+  bool HasPollingWork() const override {
+    for (auto& iter : dawn_device_and_wire_servers_) {
+      if (iter.second->HasPollingWork()) {
+        return true;
+      }
+    }
+    return false;
+  }
 
   void PerformPollingWork() override {
     TRACE_EVENT0(TRACE_DISABLED_BY_DEFAULT("gpu.dawn"),