Add builders for tracing event's structural arguments

cc/resources/tile_priority.cc

Index: cc/resources/tile_priority.cc
diff --git a/cc/resources/tile_priority.cc b/cc/resources/tile_priority.cc
index 18678d2123ba4f0bc00a806d8dda42513bd0c787..26826af450e192fd6b0f60fba13fa2198478d63d 100644
--- a/cc/resources/tile_priority.cc
+++ b/cc/resources/tile_priority.cc
@@ -4,110 +4,95 @@
 
 #include "cc/resources/tile_priority.h"
 
+#include "base/debug/trace_event_argument.h"
 #include "base/values.h"
 #include "cc/base/math_util.h"
 
 namespace cc {
 
-scoped_ptr<base::Value> WhichTreeAsValue(WhichTree tree) {
+std::string WhichTreeToString(WhichTree tree) {
   switch (tree) {
   case ACTIVE_TREE:
-      return scoped_ptr<base::Value>(new base::StringValue("ACTIVE_TREE"));
+    return "ACTIVE_TREE";
   case PENDING_TREE:
-      return scoped_ptr<base::Value>(new base::StringValue("PENDING_TREE"));
+    return "PENDING_TREE";
   default:
       DCHECK(false) << "Unrecognized WhichTree value " << tree;
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "<unknown WhichTree value>"));
+      return "<unknown WhichTree value>";
   }
 }
 
-scoped_ptr<base::Value> TileResolutionAsValue(
-    TileResolution resolution) {
+std::string TileResolutionToString(TileResolution resolution) {
   switch (resolution) {
   case LOW_RESOLUTION:
-    return scoped_ptr<base::Value>(new base::StringValue("LOW_RESOLUTION"));
+    return "LOW_RESOLUTION";
   case HIGH_RESOLUTION:
-    return scoped_ptr<base::Value>(new base::StringValue("HIGH_RESOLUTION"));
+    return "HIGH_RESOLUTION";
   case NON_IDEAL_RESOLUTION:
-      return scoped_ptr<base::Value>(new base::StringValue(
-        "NON_IDEAL_RESOLUTION"));
+    return "NON_IDEAL_RESOLUTION";
   }
   DCHECK(false) << "Unrecognized TileResolution value " << resolution;
-  return scoped_ptr<base::Value>(new base::StringValue(
-      "<unknown TileResolution value>"));
+  return "<unknown TileResolution value>";
 }
 
-scoped_ptr<base::Value> TilePriorityBinAsValue(TilePriority::PriorityBin bin) {
+std::string TilePriorityBinToString(TilePriority::PriorityBin bin) {
   switch (bin) {
     case TilePriority::NOW:
-      return scoped_ptr<base::Value>(new base::StringValue("NOW"));
+      return "NOW";
     case TilePriority::SOON:
-      return scoped_ptr<base::Value>(new base::StringValue("SOON"));
+      return "SOON";
     case TilePriority::EVENTUALLY:
-      return scoped_ptr<base::Value>(new base::StringValue("EVENTUALLY"));
+      return "EVENTUALLY";
   }
   DCHECK(false) << "Unrecognized TilePriority::PriorityBin value " << bin;
-  return scoped_ptr<base::Value>(
-      new base::StringValue("<unknown TilePriority::PriorityBin value>"));
+  return "<unknown TilePriority::PriorityBin value>";
 }
 
-scoped_ptr<base::Value> TilePriority::AsValue() const {
-  scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
-  state->Set("resolution", TileResolutionAsValue(resolution).release());
-  state->Set("priority_bin", TilePriorityBinAsValue(priority_bin).release());
-  state->Set("distance_to_visible",
-             MathUtil::AsValueSafely(distance_to_visible).release());
-  return state.PassAs<base::Value>();
+void TilePriority::AsValueInto(base::debug::TracedValue* state) const {
+  state->SetString("resolution", TileResolutionToString(resolution));
+  state->SetString("priority_bin", TilePriorityBinToString(priority_bin));
+  state->SetDouble("distance_to_visible",
+                   MathUtil::AsDoubleSafely(distance_to_visible));
 }
 
-scoped_ptr<base::Value> TileMemoryLimitPolicyAsValue(
-    TileMemoryLimitPolicy policy) {
+std::string TileMemoryLimitPolicyToString(TileMemoryLimitPolicy policy) {
   switch (policy) {
   case ALLOW_NOTHING:
-      return scoped_ptr<base::Value>(new base::StringValue("ALLOW_NOTHING"));
+    return "ALLOW_NOTHING";
   case ALLOW_ABSOLUTE_MINIMUM:
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "ALLOW_ABSOLUTE_MINIMUM"));
+    return "ALLOW_ABSOLUTE_MINIMUM";
   case ALLOW_PREPAINT_ONLY:
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "ALLOW_PREPAINT_ONLY"));
+    return "ALLOW_PREPAINT_ONLY";
   case ALLOW_ANYTHING:
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "ALLOW_ANYTHING"));
+    return "ALLOW_ANYTHING";
   default:
       DCHECK(false) << "Unrecognized policy value";
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "<unknown>"));
+      return "<unknown>";
   }
 }
 
-scoped_ptr<base::Value> TreePriorityAsValue(TreePriority prio) {
+std::string TreePriorityToString(TreePriority prio) {
   switch (prio) {
   case SAME_PRIORITY_FOR_BOTH_TREES:
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "SAME_PRIORITY_FOR_BOTH_TREES"));
+    return "SAME_PRIORITY_FOR_BOTH_TREES";
   case SMOOTHNESS_TAKES_PRIORITY:
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "SMOOTHNESS_TAKES_PRIORITY"));
+    return "SMOOTHNESS_TAKES_PRIORITY";
   case NEW_CONTENT_TAKES_PRIORITY:
-      return scoped_ptr<base::Value>(new base::StringValue(
-          "NEW_CONTENT_TAKES_PRIORITY"));
+    return "NEW_CONTENT_TAKES_PRIORITY";
   default:
     DCHECK(false) << "Unrecognized priority value " << prio;
-    return scoped_ptr<base::Value>(new base::StringValue("<unknown>"));
+    return "<unknown>";
   }
 }
 
-scoped_ptr<base::Value> GlobalStateThatImpactsTilePriority::AsValue() const {
-  scoped_ptr<base::DictionaryValue> state(new base::DictionaryValue());
-  state->Set("memory_limit_policy",
-             TileMemoryLimitPolicyAsValue(memory_limit_policy).release());
+void GlobalStateThatImpactsTilePriority::AsValueInto(
+    base::debug::TracedValue* state) const {
+  state->SetString("memory_limit_policy",
+                   TileMemoryLimitPolicyToString(memory_limit_policy));
   state->SetInteger("soft_memory_limit_in_bytes", soft_memory_limit_in_bytes);
   state->SetInteger("hard_memory_limit_in_bytes", hard_memory_limit_in_bytes);
   state->SetInteger("num_resources_limit", num_resources_limit);
-  state->Set("tree_priority", TreePriorityAsValue(tree_priority).release());
-  return state.PassAs<base::Value>();
+  state->SetString("tree_priority", TreePriorityToString(tree_priority));
 }
 
 }  // namespace cc