Added methods to generate sync tokens for resource id(s).

New functions have been added so a sync token can represent
multiple resources at once. Adding a single sync token at
the end of generating a multitude of resources can be a win.

The most obvious use cases of this is the video layer which
generates a resource for each layer. A single sync token is
now generated at the end of the layer generation.

The layer tree UI resource also generates its own sync token.

BUG=584381
CQ_INCLUDE_TRYBOTS=tryserver.blink:linux_blink_rel

Review URL: https://codereview.chromium.org/1707143002

Cr-Commit-Position: refs/heads/master@{#376039}

cc/layers/video_layer_impl.cc

@@ -124,6 +124,8 @@ bool VideoLayerImpl::WillDraw(DrawMode draw_mode,
 
   DCHECK_EQ(external_resources.mailboxes.size(),
             external_resources.release_callbacks.size());
+  ResourceProvider::ResourceIdArray resource_ids;
+  resource_ids.reserve(external_resources.mailboxes.size());
   for (size_t i = 0; i < external_resources.mailboxes.size(); ++i) {
     unsigned resource_id = resource_provider->CreateResourceFromTextureMailbox(
         external_resources.mailboxes[i],
@@ -133,7 +135,9 @@ bool VideoLayerImpl::WillDraw(DrawMode draw_mode,
     frame_resources_.push_back(FrameResource(
         resource_id, external_resources.mailboxes[i].size_in_pixels(),
         external_resources.mailboxes[i].is_overlay_candidate()));
+    resource_ids.push_back(resource_id);
   }
+  resource_provider->GenerateSyncTokenForResources(resource_ids);
 
   return true;
 }

cc/resources/resource_provider.cc

@@ -753,6 +753,44 @@ void ResourceProvider::CopyToResource(ResourceId id,
   }
 }
 
+void ResourceProvider::GenerateSyncTokenForResource(ResourceId resource_id) {
+  Resource* resource = GetResource(resource_id);
+  if (!resource->needs_sync_token())
+    return;
+
+  gpu::SyncToken sync_token;
+  GLES2Interface* gl = ContextGL();
+  DCHECK(gl);
+
+  const uint64_t fence_sync = gl->InsertFenceSyncCHROMIUM();
+  gl->OrderingBarrierCHROMIUM();
+  gl->GenUnverifiedSyncTokenCHROMIUM(fence_sync, sync_token.GetData());
+
+  resource->UpdateSyncToken(sync_token);
+}
+
+void ResourceProvider::GenerateSyncTokenForResources(
+    const ResourceIdArray& resource_ids) {
+  gpu::SyncToken sync_token;
+  bool created_sync_token = false;
+  for (ResourceId id : resource_ids) {
+    Resource* resource = GetResource(id);
+    if (resource->needs_sync_token()) {
+      if (!created_sync_token) {
+        GLES2Interface* gl = ContextGL();
+        DCHECK(gl);
+
+        const uint64_t fence_sync = gl->InsertFenceSyncCHROMIUM();
+        gl->OrderingBarrierCHROMIUM();
+        gl->GenUnverifiedSyncTokenCHROMIUM(fence_sync, sync_token.GetData());
+        created_sync_token = true;
+      }
+
+      resource->UpdateSyncToken(sync_token);
+    }
+  }
+}
+
 ResourceProvider::Resource* ResourceProvider::InsertResource(
     ResourceId id,
     const Resource& resource) {

cc/resources/resource_provider.h

@@ -159,9 +159,9 @@ class CC_EXPORT ResourceProvider
                       const uint8_t* image,
                       const gfx::Size& image_size);
 
-  // Only flush the command buffer if supported.
-  // Returns true if the shallow flush occurred, false otherwise.
-  bool ShallowFlushIfSupported();
+  // Generates sync tokesn for resources which need a sync token.
+  void GenerateSyncTokenForResource(ResourceId resource_id);
+  void GenerateSyncTokenForResources(const ResourceIdArray& resource_ids);
 
   // Creates accounting for a child. Returns a child ID.
   int CreateChild(const ReturnCallback& return_callback);

cc/trees/layer_tree_host_impl.cc

@@ -3648,6 +3648,8 @@ void LayerTreeHostImpl::CreateUIResource(UIResourceId uid,
   AutoLockUIResourceBitmap bitmap_lock(bitmap);
   resource_provider_->CopyToResource(id, bitmap_lock.GetPixels(),
                                      bitmap.GetSize());
+
+  resource_provider_->GenerateSyncTokenForResource(id);
   MarkUIResourceNotEvicted(uid);
 }