Add builders for tracing event's structural arguments

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index 2544c0d78c8212af790d6679a18b48e7eec8122d..dcbcc7474a0d1ed0a0fb9aac6a1377e24d6c49b2 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <limits>
 
+#include "base/debug/trace_event_argument.h"
 #include "base/time/time.h"
 #include "cc/base/math_util.h"
 #include "cc/base/util.h"
@@ -1335,31 +1336,42 @@ void PictureLayerImpl::GetDebugBorderProperties(
   *width = DebugColors::TiledContentLayerBorderWidth(layer_tree_impl());
 }
 
-void PictureLayerImpl::AsValueInto(base::DictionaryValue* state) const {
+void PictureLayerImpl::AsValueInto(base::debug::TracedValue* state) const {
   const_cast<PictureLayerImpl*>(this)->DoPostCommitInitializationIfNeeded();
   LayerImpl::AsValueInto(state);
   state->SetDouble("ideal_contents_scale", ideal_contents_scale_);
   state->SetDouble("geometry_contents_scale", MaximumTilingContentsScale());
-  state->Set("tilings", tilings_->AsValue().release());
-  state->Set("pictures", pile_->AsValue().release());
-  state->Set("invalidation", invalidation_.AsValue().release());
+  state->BeginArray("tilings");
+  tilings_->AsValueInto(state);
+  state->EndArray();
 
-  scoped_ptr<base::ListValue> coverage_tiles(new base::ListValue);
+  state->BeginArray("pictures");
+  pile_->AsValueInto(state);
+  state->EndArray();
+
+  state->BeginArray("invalidation");
+  invalidation_.AsValueInto(state);
+  state->EndArray();
+
+  state->BeginArray("coverage_tiles");
   for (PictureLayerTilingSet::CoverageIterator iter(tilings_.get(),
                                                     contents_scale_x(),
                                                     gfx::Rect(content_bounds()),
                                                     ideal_contents_scale_);
        iter;
        ++iter) {
-    scoped_ptr<base::DictionaryValue> tile_data(new base::DictionaryValue);
-    tile_data->Set("geometry_rect",
-                   MathUtil::AsValue(iter.geometry_rect()).release());
+    state->BeginDictionary();
+
+    state->BeginArray("geometry_rect");
+    MathUtil::AddToTracedValue(iter.geometry_rect(), state);
+    state->EndArray();
+
     if (*iter)
-      tile_data->Set("tile", TracedValue::CreateIDRef(*iter).release());
+      TracedValue::SetIDRef(*iter, state, "tile");
 
-    coverage_tiles->Append(tile_data.release());
+    state->EndDictionary();
   }
-  state->Set("coverage_tiles", coverage_tiles.release());
+  state->EndArray();
 }
 
 size_t PictureLayerImpl::GPUMemoryUsageInBytes() const {