cc: Add invalidation micro benchmark.

cc/debug/invalidation_benchmark.cc

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "cc/debug/invalidation_benchmark.h"
+
+#include <algorithm>
+
+#include "base/basictypes.h"
+#include "base/rand_util.h"
+#include "base/values.h"
+#include "cc/layers/layer.h"
+#include "cc/layers/picture_layer.h"
+#include "cc/trees/layer_tree_host.h"
+#include "cc/trees/layer_tree_host_common.h"
+#include "ui/gfx/rect.h"
+
+namespace cc {
+
+namespace {
+
+const char* kDefaultInvalidationMode = "viewport";
+
+}  // namespace
+
+InvalidationBenchmark::InvalidationBenchmark(
+    scoped_ptr<base::Value> value,
+    const MicroBenchmark::DoneCallback& callback)
+    : MicroBenchmark(callback), mode_(kDefaultInvalidationMode) {
+  base::DictionaryValue* settings = NULL;
+  value->GetAsDictionary(&settings);
+  if (!settings)
+    return;
+
+  if (settings->HasKey("mode"))
+    settings->GetString("mode", &mode_);
+}
+
+InvalidationBenchmark::~InvalidationBenchmark() {
+}
+
+void InvalidationBenchmark::DidUpdateLayers(LayerTreeHost* host) {
+  LayerTreeHostCommon::CallFunctionForSubtree(
+      host->root_layer(),
+      base::Bind(&InvalidationBenchmark::Run, base::Unretained(this)));
+}
+
+void InvalidationBenchmark::Run(Layer* layer) {
+  layer->RunMicroBenchmark(this);
+}
+
+void InvalidationBenchmark::RunOnLayer(PictureLayer* layer) {
+  if (mode_ == "layer") {
+    // Invalidate entire layer.
+    layer->SetNeedsDisplay();
+  } else if (mode_ == "random") {
+    // Random invalidation inside the viewport.
+    gfx::Rect visible_content_rect = layer->visible_content_rect();
+    int x_min = base::RandInt(0, visible_content_rect.width());
+    int x_max = base::RandInt(0, visible_content_rect.width());
+    int y_min = base::RandInt(0, visible_content_rect.height());
+    int y_max = base::RandInt(0, visible_content_rect.height());
+    if (x_min > x_max)
+      std::swap(x_min, x_max);
+    if (y_min > y_max)
+      std::swap(y_min, y_max);
+    gfx::Rect invalidation_rect(x_min, y_min, x_max - x_min, y_max - y_min);
+    layer->SetNeedsDisplayRect(invalidation_rect);
+  } else if (mode_ == "viewport") {
+    // Invalidate entire viewport.
+    layer->SetNeedsDisplayRect(layer->visible_content_rect());
+  } else {
+    NOTREACHED();

[vmpstr, 2014/05/27 18:29:22]

can you
NOTREACHED() << "Invalid mode: " << mode_ << ". One of {layer, random, viewport}
expected";

or something similar instead? Since this is a user specified value, it might be
worth it to have a more verbose message.

I would also do the verification in the constructor and convert it to an enum so
that the scope of relying on user specified values is limited, but that's up to
you if you wanna do that.

[ernstm, 2014/05/27 21:17:07]

Done.

+  }
+}
+
+}  // namespace cc