Combine traits for IPC mutation and generation fuzzing plus other refactoring.

tools/ipc_fuzzer/mutate/fuzzer.cc

+// Copyright 2015 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 <iostream>
+#include <set>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "base/strings/string_util.h"
+#include "ipc/ipc_message.h"
+#include "ipc/ipc_message_utils.h"
+#include "ipc/ipc_switches.h"
+#include "ipc/ipc_sync_channel.h"
+#include "ipc/ipc_sync_message.h"
+#include "tools/ipc_fuzzer/message_lib/message_file.h"
+#include "tools/ipc_fuzzer/mutate/fuzzer.h"
+#include "tools/ipc_fuzzer/mutate/rand_util.h"
+
+#if defined(OS_POSIX)
+#include <unistd.h>
+#endif
+
+// First include of message files to provide basic type.
+#include "tools/ipc_fuzzer/message_lib/all_messages.h"
+#include "ipc/ipc_message_null_macros.h"
+
+#if defined(COMPILER_GCC)
+#define PRETTY_FUNCTION __PRETTY_FUNCTION__
+#elif defined(COMPILER_MSVC)
+#define PRETTY_FUNCTION __FUNCSIG__
+#else
+#define PRETTY_FUNCTION __FUNCTION__
+#endif
+
+namespace IPC {
+class Message;
+}  // namespace IPC
+
+namespace {
+// For breaking deep recursion.
+int g_depth = 0;
+}  // namespace
+
+namespace ipc_fuzzer {
+
+FuzzerFunctionVector g_function_vector;
+
+bool Fuzzer::ShouldGenerate() {
+  return false;
+}
+
+// Partially-specialized class that knows how to handle a given type.
+template <class P>
+struct FuzzTraits {
+  static bool Fuzz(P* p, Fuzzer *fuzzer) {
+    // This is the catch-all for types we don't have enough information
+    // to generate.
+    std::cerr << "Can't handle " << PRETTY_FUNCTION << "\n";
+    return false;
+  }
+};
+
+// Template function to invoke partially-specialized class method.
+template <class P>
+static bool FuzzParam(P* p, Fuzzer* fuzzer) {
+  return FuzzTraits<P>::Fuzz(p, fuzzer);
+}
+
+template <class P>
+static bool FuzzParamArray(P* p, size_t length, Fuzzer* fuzzer) {
+  for (size_t i = 0; i < length; i++, p++) {
+    if (!FuzzTraits<P>::Fuzz(p, fuzzer))
+      return false;
+  }
+  return true;
+}
+
+// Specializations to generate primitive types.
+template <>
+struct FuzzTraits<bool> {
+  static bool Fuzz(bool* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzBool(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<int> {
+  static bool Fuzz(int* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzInt(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<unsigned int> {
+  static bool Fuzz(unsigned int* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzInt(reinterpret_cast<int*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<long> {
+  static bool Fuzz(long* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzLong(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<unsigned long> {
+  static bool Fuzz(unsigned long* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzLong(reinterpret_cast<long*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<long long> {
+  static bool Fuzz(long long* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzInt64(reinterpret_cast<int64*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<unsigned long long> {
+  static bool Fuzz(unsigned long long* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzInt64(reinterpret_cast<int64*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<short> {
+  static bool Fuzz(short* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzUInt16(reinterpret_cast<uint16*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<unsigned short> {
+  static bool Fuzz(unsigned short* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzUInt16(reinterpret_cast<uint16*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<char> {
+  static bool Fuzz(char* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzUChar(reinterpret_cast<unsigned char*>(p));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<unsigned char> {
+  static bool Fuzz(unsigned char* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzUChar(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<wchar_t> {
+  static bool Fuzz(wchar_t* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzWChar(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<float> {
+  static bool Fuzz(float* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzFloat(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<double> {
+  static bool Fuzz(double* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzDouble(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<std::string> {
+  static bool Fuzz(std::string* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzString(p);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::string16> {
+  static bool Fuzz(base::string16* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzString16(p);
+    return true;
+  }
+};
+
+// Specializations for tuples.
+template <>
+struct FuzzTraits<Tuple<>> {
+  static bool Fuzz(Tuple<>* p, Fuzzer* fuzzer) {
+    return true;
+  }
+};
+
+template <class A>
+struct FuzzTraits<Tuple<A>> {
+  static bool Fuzz(Tuple<A>* p, Fuzzer* fuzzer) {
+    return FuzzParam(&get<0>(*p), fuzzer);
+  }
+};
+
+template <class A, class B>
+struct FuzzTraits<Tuple<A, B>> {
+  static bool Fuzz(Tuple<A, B>* p, Fuzzer* fuzzer) {
+    return
+        FuzzParam(&get<0>(*p), fuzzer) &&
+        FuzzParam(&get<1>(*p), fuzzer);
+  }
+};
+
+template <class A, class B, class C>
+struct FuzzTraits<Tuple<A, B, C>> {
+  static bool Fuzz(Tuple<A, B, C>* p, Fuzzer* fuzzer) {
+    return
+        FuzzParam(&get<0>(*p), fuzzer) &&
+        FuzzParam(&get<1>(*p), fuzzer) &&
+        FuzzParam(&get<2>(*p), fuzzer);
+  }
+};
+
+template <class A, class B, class C, class D>
+struct FuzzTraits<Tuple<A, B, C, D>> {
+  static bool Fuzz(Tuple<A, B, C, D>* p, Fuzzer* fuzzer) {
+    return
+        FuzzParam(&get<0>(*p), fuzzer) &&
+        FuzzParam(&get<1>(*p), fuzzer) &&
+        FuzzParam(&get<2>(*p), fuzzer) &&
+        FuzzParam(&get<3>(*p), fuzzer);
+  }
+};
+
+template <class A, class B, class C, class D, class E>
+struct FuzzTraits<Tuple<A, B, C, D, E>> {
+  static bool Fuzz(Tuple<A, B, C, D, E>* p, Fuzzer* fuzzer) {
+    return
+        FuzzParam(&get<0>(*p), fuzzer) &&
+        FuzzParam(&get<1>(*p), fuzzer) &&
+        FuzzParam(&get<2>(*p), fuzzer) &&
+        FuzzParam(&get<3>(*p), fuzzer) &&
+        FuzzParam(&get<4>(*p), fuzzer);
+  }
+};
+
+// Specializations for containers.
+template <class A>
+struct FuzzTraits<std::vector<A> > {
+  static bool Fuzz(std::vector<A>* p, Fuzzer* fuzzer) {
+    ++g_depth;
+    size_t count = p->size();
+    if (fuzzer->ShouldGenerate()) {
+      count = g_depth > 3 ? 0 : RandElementCount();
+      p->resize(count);
+    }
+    for (size_t i = 0; i < count; ++i) {
+      if (!FuzzParam(&p->at(i), fuzzer)) {
+        --g_depth;
+        return false;
+      }
+    }
+    --g_depth;
+    return true;
+  }
+};
+
+template <class A>
+struct FuzzTraits<std::set<A> > {
+  static bool Fuzz(std::set<A>* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    static int g_depth = 0;
+    size_t count = ++g_depth > 3 ? 0 : RandElementCount();
+    A a;
+    for (size_t i = 0; i < count; ++i) {
+      if (!FuzzParam(&a, fuzzer)) {
+        --g_depth;
+        return false;
+      }
+      p->insert(a);
+    }
+    --g_depth;
+    return true;
+  }
+};
+
+template <class A, class B>
+struct FuzzTraits<std::map<A, B> > {
+  static bool Fuzz(std::map<A, B>* p, Fuzzer* fuzzer) {
+    if (!fuzzer->ShouldGenerate()) {
+      typename std::map<A, B>::iterator it;
+      for (it = p->begin(); it != p->end(); ++it) {
+        FuzzParam(&it->second, fuzzer);
+      }
+      return true;
+    }
+
+    static int g_depth = 0;
+    size_t count = ++g_depth > 3 ? 0 : RandElementCount();
+    std::pair<A, B> place_holder;
+    for (size_t i = 0; i < count; ++i) {
+      if (!FuzzParam(&place_holder, fuzzer)) {
+        --g_depth;
+        return false;
+      }
+      p->insert(place_holder);
+    }
+    --g_depth;
+    return true;
+  }
+};
+
+template <class A, class B, class C, class D>
+struct FuzzTraits<std::map<A, B, C, D>> {
+  static bool Fuzz(std::map<A, B, C, D>* p, Fuzzer* fuzzer) {
+    if (!fuzzer->ShouldGenerate()) {
+      typename std::map<A, B, C, D>::iterator it;
+      for (it = p->begin(); it != p->end(); ++it) {
+        FuzzParam(&it->second, fuzzer);
+      }
+      return true;
+    }
+
+    static int g_depth = 0;
+    size_t count = ++g_depth > 3 ? 0 : RandElementCount();
+    std::pair<A, B> place_holder;
+    for (size_t i = 0; i < count; ++i) {
+      if (!FuzzParam(&place_holder, fuzzer)) {
+        --g_depth;
+        return false;
+      }
+      p->insert(place_holder);
+    }
+    --g_depth;
+    return true;
+  }
+};
+
+template <class A, class B>
+struct FuzzTraits<std::pair<A, B> > {
+  static bool Fuzz(std::pair<A, B>* p, Fuzzer* fuzzer) {
+    return
+        FuzzParam(&p->first, fuzzer) &&
+        FuzzParam(&p->second, fuzzer);
+  }
+};
+
+// Specializations for hand-coded types.
+
+template <>
+struct FuzzTraits<base::FilePath> {
+  static bool Fuzz(base::FilePath* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    const char path_chars[] = "ACz0/.~:";
+    size_t count = RandInRange(60);
+    base::FilePath::StringType random_path;
+    for (size_t i = 0; i < count; ++i)
+      random_path += path_chars[RandInRange(sizeof(path_chars) - 1)];
+    *p = base::FilePath(random_path);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::File::Error> {
+  static bool Fuzz(base::File::Error* p, Fuzzer* fuzzer) {
+    int value = static_cast<int>(*p);
+    if (!FuzzParam(&value, fuzzer))
+      return false;
+    *p = static_cast<base::File::Error>(value);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::File::Info> {
+  static bool Fuzz(base::File::Info* p, Fuzzer* fuzzer) {
+    double last_modified = p->last_modified.ToDoubleT();
+    double last_accessed = p->last_accessed.ToDoubleT();
+    double creation_time = p->creation_time.ToDoubleT();
+    if (!FuzzParam(&p->size, fuzzer))
+      return false;
+    if (!FuzzParam(&p->is_directory, fuzzer))
+      return false;
+    if (!FuzzParam(&last_modified, fuzzer))
+      return false;
+    if (!FuzzParam(&last_accessed, fuzzer))
+      return false;
+    if (!FuzzParam(&creation_time, fuzzer))
+      return false;
+    p->last_modified = base::Time::FromDoubleT(last_modified);
+    p->last_accessed = base::Time::FromDoubleT(last_accessed);
+    p->creation_time = base::Time::FromDoubleT(creation_time);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::NullableString16> {
+  static bool Fuzz(base::NullableString16* p, Fuzzer* fuzzer) {
+    base::string16 string = p->string();
+    bool is_null = p->is_null();
+    if (!FuzzParam(&string, fuzzer))
+      return false;
+    if (!FuzzParam(&is_null, fuzzer))
+      return false;
+    *p = base::NullableString16(string, is_null);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::Time> {
+  static bool Fuzz(base::Time* p, Fuzzer* fuzzer) {
+    int64 internal_value = p->ToInternalValue();
+    if (!FuzzParam(&internal_value, fuzzer))
+      return false;
+    *p = base::Time::FromInternalValue(internal_value);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::TimeDelta> {
+  static bool Fuzz(base::TimeDelta* p, Fuzzer* fuzzer) {
+    int64 internal_value = p->ToInternalValue();
+    if (!FuzzParam(&internal_value, fuzzer))
+      return false;
+    *p = base::TimeDelta::FromInternalValue(internal_value);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::TimeTicks> {
+  static bool Fuzz(base::TimeTicks* p, Fuzzer* fuzzer) {
+    int64 internal_value = p->ToInternalValue();
+    if (!FuzzParam(&internal_value, fuzzer))
+      return false;
+    *p = base::TimeTicks::FromInternalValue(internal_value);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::ListValue> {
+  static bool Fuzz(base::ListValue* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    ++g_depth;
+    size_t list_length = g_depth > 3 ? 0 : RandInRange(8);
+    for (size_t index = 0; index < list_length; ++index) {
+      switch (RandInRange(8)) {
+        case base::Value::TYPE_BOOLEAN: {
+          bool tmp;
+          fuzzer->FuzzBool(&tmp);
+          p->Set(index, new base::FundamentalValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_INTEGER: {
+          int tmp;
+          fuzzer->FuzzInt(&tmp);
+          p->Set(index, new base::FundamentalValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_DOUBLE: {
+          double tmp;
+          fuzzer->FuzzDouble(&tmp);
+          p->Set(index, new base::FundamentalValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_STRING: {
+          std::string tmp;
+          fuzzer->FuzzString(&tmp);
+          p->Set(index, new base::StringValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_BINARY: {
+          char tmp[200];
+          size_t bin_length = RandInRange(sizeof(tmp));
+          fuzzer->FuzzData(tmp, bin_length);
+          p->Set(index,
+                 base::BinaryValue::CreateWithCopiedBuffer(tmp, bin_length));
+          break;
+        }
+        case base::Value::TYPE_DICTIONARY: {
+          base::DictionaryValue* tmp = new base::DictionaryValue();
+          FuzzParam(tmp, fuzzer);
+          p->Set(index, tmp);
+          break;
+        }
+        case base::Value::TYPE_LIST: {
+          base::ListValue* tmp = new base::ListValue();
+          FuzzParam(tmp, fuzzer);
+          p->Set(index, tmp);
+          break;
+        }
+        case base::Value::TYPE_NULL:
+        default:
+          break;
+      }
+    }
+    --g_depth;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<base::DictionaryValue> {
+  static bool Fuzz(base::DictionaryValue* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    ++g_depth;
+    size_t dict_length = g_depth > 3 ? 0 : RandInRange(8);
+    for (size_t index = 0; index < dict_length; ++index) {
+      std::string property;
+      fuzzer->FuzzString(&property);
+      switch (RandInRange(8)) {
+        case base::Value::TYPE_BOOLEAN: {
+          bool tmp;
+          fuzzer->FuzzBool(&tmp);
+          p->SetWithoutPathExpansion(property, new base::FundamentalValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_INTEGER: {
+          int tmp;
+          fuzzer->FuzzInt(&tmp);
+          p->SetWithoutPathExpansion(property, new base::FundamentalValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_DOUBLE: {
+          double tmp;
+          fuzzer->FuzzDouble(&tmp);
+          p->SetWithoutPathExpansion(property, new base::FundamentalValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_STRING: {
+          std::string tmp;
+          fuzzer->FuzzString(&tmp);
+          p->SetWithoutPathExpansion(property, new base::StringValue(tmp));
+          break;
+        }
+        case base::Value::TYPE_BINARY: {
+          char tmp[200];
+          size_t bin_length = RandInRange(sizeof(tmp));
+          fuzzer->FuzzData(tmp, bin_length);
+          p->SetWithoutPathExpansion(
+              property,
+              base::BinaryValue::CreateWithCopiedBuffer(tmp, bin_length));
+          break;
+        }
+        case base::Value::TYPE_DICTIONARY: {
+          base::DictionaryValue* tmp = new base::DictionaryValue();
+          FuzzParam(tmp, fuzzer);
+          p->SetWithoutPathExpansion(property, tmp);
+          break;
+        }
+        case base::Value::TYPE_LIST: {
+          base::ListValue* tmp = new base::ListValue();
+          FuzzParam(tmp, fuzzer);
+          p->SetWithoutPathExpansion(property, tmp);
+          break;
+        }
+        case base::Value::TYPE_NULL:
+        default:
+          break;
+      }
+    }
+    --g_depth;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<blink::WebGamepad> {
+  static bool Fuzz(blink::WebGamepad* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->connected, fuzzer))
+      return false;
+    if (!FuzzParam(&p->timestamp, fuzzer))
+      return false;
+    unsigned idLength = static_cast<unsigned>(
+        RandInRange(blink::WebGamepad::idLengthCap + 1));
+    if (!FuzzParamArray(&p->id[0], idLength, fuzzer))
+      return false;
+    p->axesLength = static_cast<unsigned>(
+        RandInRange(blink::WebGamepad::axesLengthCap + 1));
+    if (!FuzzParamArray(&p->axes[0], p->axesLength, fuzzer))
+      return false;
+    p->buttonsLength = static_cast<unsigned>(
+        RandInRange(blink::WebGamepad::buttonsLengthCap + 1));
+    if (!FuzzParamArray(&p->buttons[0], p->buttonsLength, fuzzer))
+      return false;
+    unsigned mappingsLength = static_cast<unsigned>(
+      RandInRange(blink::WebGamepad::mappingLengthCap + 1));
+    if (!FuzzParamArray(&p->mapping[0], mappingsLength, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<blink::WebGamepadButton> {
+  static bool Fuzz(blink::WebGamepadButton* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->pressed, fuzzer))
+      return false;
+    if (!FuzzParam(&p->value, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<cc::CompositorFrame> {
+  static bool Fuzz(cc::CompositorFrame* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    if (!FuzzParam(&p->metadata, fuzzer))
+      return false;
+
+    switch (RandInRange(4)) {
+      case 0: {
+        p->delegated_frame_data.reset(new cc::DelegatedFrameData());
+        if (!FuzzParam(p->delegated_frame_data.get(), fuzzer))
+          return false;
+        return true;
+      }
+      case 1: {
+        p->gl_frame_data.reset(new cc::GLFrameData());
+        if (!FuzzParam(p->gl_frame_data.get(), fuzzer))
+          return false;
+        return true;
+      }
+      case 2: {
+        p->software_frame_data.reset(new cc::SoftwareFrameData());
+        if (!FuzzParam(p->software_frame_data.get(), fuzzer))
+          return false;
+        return true;
+      }
+      default:
+        // Fuzz nothing to handle the no frame case.
+        return true;
+    }
+  }
+};
+
+template <>
+struct FuzzTraits<cc::CompositorFrameAck> {
+  static bool Fuzz(cc::CompositorFrameAck* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->resources, fuzzer))
+      return false;
+    if (!FuzzParam(&p->last_software_frame_id, fuzzer))
+      return false;
+
+    if (!p->gl_frame_data)
+      p->gl_frame_data.reset(new cc::GLFrameData);
+    if (!FuzzParam(p->gl_frame_data.get(), fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<cc::DelegatedFrameData> {
+  static bool Fuzz(cc::DelegatedFrameData* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->device_scale_factor, fuzzer))
+      return false;
+    if (!FuzzParam(&p->resource_list, fuzzer))
+      return false;
+    if (!FuzzParam(&p->render_pass_list, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <class A>
+struct FuzzTraits<cc::ListContainer<A>> {
+  static bool Fuzz(cc::ListContainer<A>* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<cc::QuadList> {
+  static bool Fuzz(cc::QuadList* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<cc::RenderPass> {
+  static bool Fuzz(cc::RenderPass* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->id, fuzzer))
+      return false;
+    if (!FuzzParam(&p->output_rect, fuzzer))
+      return false;
+    if (!FuzzParam(&p->damage_rect, fuzzer))
+      return false;
+    if (!FuzzParam(&p->transform_to_root_target, fuzzer))
+      return false;
+    if (!FuzzParam(&p->has_transparent_background, fuzzer))
+      return false;
+    if (!FuzzParam(&p->quad_list, fuzzer))
+      return false;
+    if (!FuzzParam(&p->shared_quad_state_list, fuzzer))
+      return false;
+    // Omitting |copy_requests| as it is not sent over IPC.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<cc::RenderPassList> {
+  static bool Fuzz(cc::RenderPassList* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    size_t count = RandElementCount();
+    for (size_t i = 0; i < count; ++i) {
+      scoped_ptr<cc::RenderPass> render_pass = cc::RenderPass::Create();
+      if (!FuzzParam(render_pass.get(), fuzzer))
+        return false;
+      p->push_back(render_pass.Pass());
+    }
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<cc::SoftwareFrameData> {
+  static bool Fuzz(cc::SoftwareFrameData* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->id, fuzzer))
+      return false;
+    if (!FuzzParam(&p->size, fuzzer))
+      return false;
+    if (!FuzzParam(&p->damage_rect, fuzzer))
+      return false;
+    if (!FuzzParam(&p->bitmap_id, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::IndexedDBKey> {
+  static bool Fuzz(content::IndexedDBKey* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    ++g_depth;
+    blink::WebIDBKeyType web_type =
+        static_cast<blink::WebIDBKeyType>(RandInRange(7));
+    switch (web_type) {
+      case blink::WebIDBKeyTypeArray: {
+        size_t length = g_depth > 3 ? 0 : RandInRange(4);
+        std::vector<content::IndexedDBKey> array;
+        array.resize(length);
+        for (size_t i = 0; i < length; ++i) {
+            if (!FuzzParam(&array[i], fuzzer)) {
+              --g_depth;
+              return false;
+            }
+        }
+        *p = content::IndexedDBKey(array);
+        return true;
+      }
+      case blink::WebIDBKeyTypeBinary: {
+        std::string binary;
+        if (!FuzzParam(&binary, fuzzer)) {
+            --g_depth;
+            return false;
+        }
+        *p = content::IndexedDBKey(binary);
+        return true;
+      }
+      case blink::WebIDBKeyTypeString: {
+        base::string16 string;
+        if (!FuzzParam(&string, fuzzer))
+          return false;
+        *p = content::IndexedDBKey(string);
+        return true;
+      }
+      case blink::WebIDBKeyTypeDate:
+      case blink::WebIDBKeyTypeNumber: {
+        double number;
+        if (!FuzzParam(&number, fuzzer)) {
+            --g_depth;
+            return false;
+        }
+        *p = content::IndexedDBKey(number, web_type);
+        return true;
+      }
+      case blink::WebIDBKeyTypeInvalid:
+      case blink::WebIDBKeyTypeNull: {
+        *p = content::IndexedDBKey(web_type);
+        return true;
+      }
+      default: {
+          NOTREACHED();
+          --g_depth;
+          return false;
+      }
+    }
+  }
+};
+
+template <>
+struct FuzzTraits<content::IndexedDBKeyRange> {
+  static bool Fuzz(content::IndexedDBKeyRange* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    content::IndexedDBKey lower;
+    content::IndexedDBKey upper;
+    bool lower_open;
+    bool upper_open;
+    if (!FuzzParam(&lower, fuzzer))
+      return false;
+    if (!FuzzParam(&upper, fuzzer))
+      return false;
+    if (!FuzzParam(&lower_open, fuzzer))
+      return false;
+    if (!FuzzParam(&upper_open, fuzzer))
+      return false;
+    *p = content::IndexedDBKeyRange(lower, upper, lower_open, upper_open);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::IndexedDBKeyPath> {
+  static bool Fuzz(content::IndexedDBKeyPath* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    switch (RandInRange(3)) {
+      case 0: {
+        std::vector<base::string16> array;
+        if (!FuzzParam(&array, fuzzer))
+          return false;
+        *p = content::IndexedDBKeyPath(array);
+        break;
+      }
+      case 1: {
+        base::string16 string;
+        if (!FuzzParam(&string, fuzzer))
+          return false;
+        *p = content::IndexedDBKeyPath(string);
+        break;
+      }
+      case 2: {
+        *p = content::IndexedDBKeyPath();
+        break;
+      }
+    }
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::NPIdentifier_Param> {
+  static bool Fuzz(content::NPIdentifier_Param* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::NPVariant_Param> {
+  static bool Fuzz(content::NPVariant_Param* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::PageState> {
+  static bool Fuzz(content::PageState* p, Fuzzer* fuzzer) {
+    std::string data = p->ToEncodedData();
+    if (!FuzzParam(&data, fuzzer))
+      return false;
+    *p = content::PageState::CreateFromEncodedData(data);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::SyntheticGesturePacket> {
+  static bool Fuzz(content::SyntheticGesturePacket* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    scoped_ptr<content::SyntheticGestureParams> gesture_params;
+    switch (RandInRange(
+        content::SyntheticGestureParams::SYNTHETIC_GESTURE_TYPE_MAX + 1)) {
+      case content::SyntheticGestureParams::GestureType::
+          SMOOTH_SCROLL_GESTURE: {
+        content::SyntheticSmoothScrollGestureParams* params =
+            new content::SyntheticSmoothScrollGestureParams();
+        if (!FuzzParam(&params->anchor, fuzzer))
+          return false;
+        if (!FuzzParam(&params->distances, fuzzer))
+          return false;
+        if (!FuzzParam(&params->prevent_fling, fuzzer))
+          return false;
+        if (!FuzzParam(&params->speed_in_pixels_s, fuzzer))
+          return false;
+        gesture_params.reset(params);
+        break;
+      }
+      case content::SyntheticGestureParams::GestureType::SMOOTH_DRAG_GESTURE: {
+        content::SyntheticSmoothDragGestureParams* params =
+            new content::SyntheticSmoothDragGestureParams();
+        if (!FuzzParam(&params->start_point, fuzzer))
+          return false;
+        if (!FuzzParam(&params->distances, fuzzer))
+          return false;
+        if (!FuzzParam(&params->speed_in_pixels_s, fuzzer))
+          return false;
+        gesture_params.reset(params);
+        break;
+      }
+      case content::SyntheticGestureParams::GestureType::PINCH_GESTURE: {
+        content::SyntheticPinchGestureParams* params =
+            new content::SyntheticPinchGestureParams();
+        if (!FuzzParam(&params->scale_factor, fuzzer))
+          return false;
+        if (!FuzzParam(&params->anchor, fuzzer))
+          return false;
+        if (!FuzzParam(&params->relative_pointer_speed_in_pixels_s,
+                           fuzzer))
+          return false;
+        gesture_params.reset(params);
+        break;
+      }
+      case content::SyntheticGestureParams::GestureType::TAP_GESTURE: {
+        content::SyntheticTapGestureParams* params =
+            new content::SyntheticTapGestureParams();
+        if (!FuzzParam(&params->position, fuzzer))
+          return false;
+        if (!FuzzParam(&params->duration_ms, fuzzer))
+          return false;
+        gesture_params.reset(params);
+        break;
+      }
+    }
+    p->set_gesture_params(gesture_params.Pass());
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<content::WebCursor> {
+  static bool Fuzz(content::WebCursor* p, Fuzzer* fuzzer) {
+    content::WebCursor::CursorInfo info;
+    p->GetCursorInfo(&info);
+
+    // |type| enum is not validated on de-serialization, so pick random value.
+    if (!FuzzParam(reinterpret_cast<int *>(&info.type), fuzzer))
+      return false;
+    if (!FuzzParam(&info.hotspot, fuzzer))
+      return false;
+    if (!FuzzParam(&info.image_scale_factor, fuzzer))
+      return false;
+    if (!FuzzParam(&info.custom_image, fuzzer))
+      return false;
+    // Omitting |externalHandle| since it is not serialized.
+
+    // Scale factor is expected to be greater than 0, otherwise we hit
+    // a check failure.
+    info.image_scale_factor = fabs(info.image_scale_factor) + 0.001;
+
+    *p = content::WebCursor(info);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ContentSettingsPattern> {
+  static bool Fuzz(ContentSettingsPattern* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This can crash if a pattern is generated from a random
+    // string. We could carefully generate a pattern or fix pattern generation.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ExtensionMsg_PermissionSetStruct> {
+  static bool Fuzz(ExtensionMsg_PermissionSetStruct* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<extensions::URLPatternSet> {
+  static bool Fuzz(extensions::URLPatternSet* p, Fuzzer* fuzzer) {
+    std::set<URLPattern> patterns = p->patterns();
+    if (!FuzzParam(&patterns, fuzzer))
+      return false;
+    *p = extensions::URLPatternSet(patterns);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Point> {
+  static bool Fuzz(gfx::Point* p, Fuzzer* fuzzer) {
+    int x = p->x();
+    int y = p->y();
+    if (!FuzzParam(&x, fuzzer))
+      return false;
+    if (!FuzzParam(&y, fuzzer))
+      return false;
+    p->SetPoint(x, y);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::PointF> {
+  static bool Fuzz(gfx::PointF* p, Fuzzer* fuzzer) {
+    float x = p->x();
+    float y = p->y();
+    if (!FuzzParam(&x, fuzzer))
+      return false;
+    if (!FuzzParam(&y, fuzzer))
+      return false;
+    p->SetPoint(x, y);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Rect> {
+  static bool Fuzz(gfx::Rect* p, Fuzzer* fuzzer) {
+    gfx::Point origin = p->origin();
+    gfx::Size size = p->size();
+    if (!FuzzParam(&origin, fuzzer))
+      return false;
+    if (!FuzzParam(&size, fuzzer))
+      return false;
+    p->set_origin(origin);
+    p->set_size(size);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::RectF> {
+  static bool Fuzz(gfx::RectF* p, Fuzzer* fuzzer) {
+    gfx::PointF origin = p->origin();
+    gfx::SizeF size = p->size();
+    if (!FuzzParam(&origin, fuzzer))
+      return false;
+    if (!FuzzParam(&size, fuzzer))
+      return false;
+    p->set_origin(origin);
+    p->set_size(size);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Range> {
+  static bool Fuzz(gfx::Range* p, Fuzzer* fuzzer) {
+    size_t start = p->start();
+    size_t end = p->end();
+    if (!FuzzParam(&start, fuzzer))
+      return false;
+    if (!FuzzParam(&end, fuzzer))
+      return false;
+    *p = gfx::Range(start, end);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Size> {
+  static bool Fuzz(gfx::Size* p, Fuzzer* fuzzer) {
+    int width = p->width();
+    int height = p->height();
+    if (!FuzzParam(&width, fuzzer))
+      return false;
+    if (!FuzzParam(&height, fuzzer))
+      return false;
+    p->SetSize(width, height);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::SizeF> {
+  static bool Fuzz(gfx::SizeF* p, Fuzzer* fuzzer) {
+    float w;
+    float h;
+    if (!FuzzParam(&w, fuzzer))
+      return false;
+    if (!FuzzParam(&h, fuzzer))
+      return false;
+    p->SetSize(w, h);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Transform> {
+  static bool Fuzz(gfx::Transform* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    SkMScalar matrix[16];
+    if (!FuzzParamArray(&matrix[0], arraysize(matrix), fuzzer))
+      return false;
+    *p = gfx::Transform(matrix[0], matrix[1], matrix[2], matrix[3], matrix[4],
+                        matrix[5], matrix[6], matrix[7], matrix[8], matrix[9],
+                        matrix[10], matrix[11], matrix[12], matrix[13],
+                        matrix[14], matrix[15]);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Vector2d> {
+  static bool Fuzz(gfx::Vector2d* p, Fuzzer* fuzzer) {
+    int x = p->x();
+    int y = p->y();
+    if (!FuzzParam(&x, fuzzer))
+      return false;
+    if (!FuzzParam(&y, fuzzer))
+      return false;
+    *p = gfx::Vector2d(x, y);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gfx::Vector2dF> {
+  static bool Fuzz(gfx::Vector2dF* p, Fuzzer* fuzzer) {
+    float x = p->x();
+    float y = p->y();
+    if (!FuzzParam(&x, fuzzer))
+      return false;
+    if (!FuzzParam(&y, fuzzer))
+      return false;
+    *p = gfx::Vector2dF(x, y);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gpu::Mailbox> {
+  static bool Fuzz(gpu::Mailbox* p, Fuzzer* fuzzer) {
+    fuzzer->FuzzBytes(p->name, sizeof(p->name));
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gpu::MailboxHolder> {
+  static bool Fuzz(gpu::MailboxHolder* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->mailbox, fuzzer))
+      return false;
+    if (!FuzzParam(&p->texture_target, fuzzer))
+      return false;
+    if (!FuzzParam(&p->sync_point, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<gpu::ValueState> {
+  static bool Fuzz(gpu::ValueState* p, Fuzzer* fuzzer) {
+    if (!FuzzParamArray(&p->float_value[0], 4, fuzzer))
+      return false;
+    if (!FuzzParamArray(&p->int_value[0], 4, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<GURL> {
+  static bool Fuzz(GURL* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    const char url_chars[] = "Ahtp0:/.?+\\%&#";
+    size_t count = RandInRange(100);
+    std::string random_url;
+    for (size_t i = 0; i < count; ++i)
+      random_url += url_chars[RandInRange(sizeof(url_chars) - 1)];
+    int selector = RandInRange(10);
+    if (selector == 0)
+      random_url = std::string("http://") + random_url;
+    else if (selector == 1)
+      random_url = std::string("file://") + random_url;
+    else if (selector == 2)
+      random_url = std::string("javascript:") + random_url;
+    else if (selector == 2)
+      random_url = std::string("data:") + random_url;
+    *p = GURL(random_url);
+    return true;
+  }
+};
+
+#if defined(OS_WIN)
+template <>
+struct FuzzTraits<HWND> {
+  static bool Fuzz(HWND* p, Fuzzer* fuzzer) {
+    // TODO(aarya): This should actually do something.
+    return true;
+  }
+};
+#endif
+
+template <>
+struct FuzzTraits<IPC::Message> {
+  static bool Fuzz(IPC::Message* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    if (g_function_vector.empty())
+      return false;
+    size_t index = RandInRange(g_function_vector.size());
+    IPC::Message* ipc_message = (*g_function_vector[index])(NULL, fuzzer);
+    if (!ipc_message)
+      return false;
+    p = ipc_message;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<IPC::PlatformFileForTransit> {
+  static bool Fuzz(IPC::PlatformFileForTransit* p, Fuzzer* fuzzer) {
+    // TODO(inferno): I don't think we can generate real ones due to check on
+    // construct.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<IPC::ChannelHandle> {
+  static bool Fuzz(IPC::ChannelHandle* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    // TODO(inferno): Add way to generate real channel handles.
+#if defined(OS_WIN)
+    HANDLE fake_handle = (HANDLE)(RandU64());
+    p->pipe = IPC::ChannelHandle::PipeHandle(fake_handle);
+    return true;
+#elif defined(OS_POSIX)
+    return
+      FuzzParam(&p->name, fuzzer) &&
+      FuzzParam(&p->socket, fuzzer);
+#endif
+  }
+};
+
+#if defined(OS_WIN)
+template <>
+struct FuzzTraits<LOGFONT> {
+  static bool Fuzz(LOGFONT* p, Fuzzer* fuzzer) {
+    // TODO(aarya): This should actually do something.
+    return true;
+  }
+};
+#endif
+
+template <>
+struct FuzzTraits<media::AudioParameters> {
+  static bool Fuzz(media::AudioParameters* p, Fuzzer* fuzzer) {
+    int format = p->format();
+    int channel_layout = p->channel_layout();
+    int sample_rate = p->sample_rate();
+    int bits_per_sample = p->bits_per_sample();
+    int frames_per_buffer = p->frames_per_buffer();
+    int channels = p->channels();
+    int effects = p->effects();
+    if (!FuzzParam(&format, fuzzer))
+      return false;
+    if (!FuzzParam(&channel_layout, fuzzer))
+      return false;
+    if (!FuzzParam(&sample_rate, fuzzer))
+      return false;
+    if (!FuzzParam(&bits_per_sample, fuzzer))
+      return false;
+    if (!FuzzParam(&frames_per_buffer, fuzzer))
+      return false;
+    if (!FuzzParam(&channels, fuzzer))
+      return false;
+    if (!FuzzParam(&effects, fuzzer))
+      return false;
+    media::AudioParameters params(
+        static_cast<media::AudioParameters::Format>(format),
+        static_cast<media::ChannelLayout>(channel_layout), channels,
+        sample_rate, bits_per_sample, frames_per_buffer, effects);
+    *p = params;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<media::VideoCaptureFormat> {
+  static bool Fuzz(media::VideoCaptureFormat* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->frame_size, fuzzer))
+      return false;
+    if (!FuzzParam(&p->frame_rate, fuzzer))
+      return false;
+    // TODO(mbarbella): Fix this or add traits for media::VideoPixelFormat.
+    if (!FuzzParam(&p->pixel_format, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<net::LoadTimingInfo> {
+  static bool Fuzz(net::LoadTimingInfo* p, Fuzzer* fuzzer) {
+    return FuzzParam(&p->socket_log_id, fuzzer) &&
+           FuzzParam(&p->socket_reused, fuzzer) &&
+           FuzzParam(&p->request_start_time, fuzzer) &&
+           FuzzParam(&p->request_start, fuzzer) &&
+           FuzzParam(&p->proxy_resolve_start, fuzzer) &&
+           FuzzParam(&p->proxy_resolve_end, fuzzer) &&
+           FuzzParam(&p->connect_timing.dns_start, fuzzer) &&
+           FuzzParam(&p->connect_timing.dns_end, fuzzer) &&
+           FuzzParam(&p->connect_timing.connect_start, fuzzer) &&
+           FuzzParam(&p->connect_timing.connect_end, fuzzer) &&
+           FuzzParam(&p->connect_timing.ssl_start, fuzzer) &&
+           FuzzParam(&p->connect_timing.ssl_end, fuzzer) &&
+           FuzzParam(&p->send_start, fuzzer) &&
+           FuzzParam(&p->send_end, fuzzer) &&
+           FuzzParam(&p->receive_headers_end, fuzzer);
+  }
+};
+
+template <>
+struct FuzzTraits<net::HostPortPair> {
+  static bool Fuzz(net::HostPortPair* p, Fuzzer* fuzzer) {
+    std::string host = p->host();
+    uint16 port = p->port();
+    if (!FuzzParam(&host, fuzzer))
+      return false;
+    if (!FuzzParam(&port, fuzzer))
+      return false;
+    p->set_host(host);
+    p->set_port(port);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<net::IPEndPoint> {
+  static bool Fuzz(net::IPEndPoint* p, Fuzzer* fuzzer) {
+    net::IPAddressNumber address = p->address();
+    int port = p->port();
+    if (!FuzzParam(&address, fuzzer))
+      return false;
+    if (!FuzzParam(&port, fuzzer))
+      return false;
+    net::IPEndPoint ip_endpoint(address, port);
+    *p = ip_endpoint;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<network_hints::LookupRequest> {
+  static bool Fuzz(network_hints::LookupRequest* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->hostname_list, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+// PP_ traits.
+template <>
+struct FuzzTraits<PP_Bool> {
+  static bool Fuzz(PP_Bool* p, Fuzzer* fuzzer) {
+    bool tmp = PP_ToBool(*p);
+    if (!FuzzParam(&tmp, fuzzer))
+      return false;
+    *p = PP_FromBool(tmp);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<PP_KeyInformation> {
+  static bool Fuzz(PP_KeyInformation* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<PP_NetAddress_Private> {
+  static bool Fuzz(PP_NetAddress_Private* p, Fuzzer* fuzzer) {
+    p->size = RandInRange(sizeof(p->data) + 1);
+    fuzzer->FuzzBytes(&p->data, p->size);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::PPB_X509Certificate_Fields> {
+  static bool Fuzz(ppapi::PPB_X509Certificate_Fields* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::PPBFlash_DrawGlyphs_Params> {
+  static bool Fuzz(ppapi::proxy::PPBFlash_DrawGlyphs_Params* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::ResourceMessageCallParams> {
+  static bool Fuzz(
+      ppapi::proxy::ResourceMessageCallParams* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    PP_Resource resource;
+    int32_t sequence;
+    bool has_callback;
+    if (!FuzzParam(&resource, fuzzer))
+      return false;
+    if (!FuzzParam(&sequence, fuzzer))
+      return false;
+    if (!FuzzParam(&has_callback, fuzzer))
+      return false;
+    *p = ppapi::proxy::ResourceMessageCallParams(resource, sequence);
+    if (has_callback)
+      p->set_has_callback();
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::ResourceMessageReplyParams> {
+  static bool Fuzz(
+      ppapi::proxy::ResourceMessageReplyParams* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    PP_Resource resource;
+    int32_t sequence;
+    int32_t result;
+    if (!FuzzParam(&resource, fuzzer))
+      return false;
+    if (!FuzzParam(&sequence, fuzzer))
+      return false;
+    if (!FuzzParam(&result, fuzzer))
+      return false;
+    *p = ppapi::proxy::ResourceMessageReplyParams(resource, sequence);
+    p->set_result(result);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::SerializedHandle> {
+  static bool Fuzz(ppapi::proxy::SerializedHandle* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::SerializedFontDescription> {
+  static bool Fuzz(ppapi::proxy::SerializedFontDescription* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::SerializedTrueTypeFontDesc> {
+  static bool Fuzz(ppapi::proxy::SerializedTrueTypeFontDesc* p,
+                       Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::proxy::SerializedVar> {
+  static bool Fuzz(ppapi::proxy::SerializedVar* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::HostResource> {
+  static bool Fuzz(ppapi::HostResource* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    PP_Instance instance;
+    PP_Resource resource;
+    if (!FuzzParam(&instance, fuzzer))
+      return false;
+    if (!FuzzParam(&resource, fuzzer))
+      return false;
+    p->SetHostResource(instance, resource);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::PepperFilePath> {
+  static bool Fuzz(ppapi::PepperFilePath *p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    unsigned domain = RandInRange(ppapi::PepperFilePath::DOMAIN_MAX_VALID+1);
+    base::FilePath path;
+    if (!FuzzParam(&path, fuzzer))
+      return false;
+    *p = ppapi::PepperFilePath(
+        static_cast<ppapi::PepperFilePath::Domain>(domain), path);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::PpapiPermissions> {
+  static bool Fuzz(ppapi::PpapiPermissions* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    uint32_t bits;
+    if (!FuzzParam(&bits, fuzzer))
+      return false;
+    *p = ppapi::PpapiPermissions(bits);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ppapi::SocketOptionData> {
+  static bool Fuzz(ppapi::SocketOptionData* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This can be improved.
+    int32 tmp;
+    p->GetInt32(&tmp);
+    if (!FuzzParam(&tmp, fuzzer))
+      return false;
+    p->SetInt32(tmp);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<printing::PdfRenderSettings> {
+  static bool Fuzz(printing::PdfRenderSettings* p, Fuzzer* fuzzer) {
+    gfx::Rect area = p->area();
+    int dpi = p->dpi();
+    bool autorotate = p->autorotate();
+    if (!FuzzParam(&area, fuzzer))
+      return false;
+    if (!FuzzParam(&dpi, fuzzer))
+      return false;
+    if (!FuzzParam(&autorotate, fuzzer))
+      return false;
+    *p = printing::PdfRenderSettings(area, dpi, autorotate);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<remoting::ScreenResolution> {
+  static bool Fuzz(remoting::ScreenResolution* p, Fuzzer* fuzzer) {
+    webrtc::DesktopSize dimensions = p->dimensions();
+    webrtc::DesktopVector dpi = p->dpi();
+    if (!FuzzParam(&dimensions, fuzzer))
+      return false;
+    if (!FuzzParam(&dpi, fuzzer))
+      return false;
+    *p = remoting::ScreenResolution(dimensions, dpi);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<SkBitmap> {
+  static bool Fuzz(SkBitmap* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): This should actually do something.
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<storage::DataElement> {
+  static bool Fuzz(storage::DataElement* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    switch (RandInRange(4)) {
+      case storage::DataElement::Type::TYPE_BYTES: {
+        if (RandEvent(2)) {
+          p->SetToEmptyBytes();
+        } else {
+          // TODO(mbarbella): Occasionally send more data here.
+          char data[256];
+          int data_len = RandInRange(sizeof(data));
+          fuzzer->FuzzBytes(&data[0], data_len);
+          p->SetToBytes(&data[0], data_len);
+        }
+        return true;
+      }
+      case storage::DataElement::Type::TYPE_FILE: {
+        base::FilePath path;
+        uint64 offset;
+        uint64 length;
+        base::Time modification_time;
+        if (!FuzzParam(&path, fuzzer))
+          return false;
+        if (!FuzzParam(&offset, fuzzer))
+          return false;
+        if (!FuzzParam(&length, fuzzer))
+          return false;
+        if (!FuzzParam(&modification_time, fuzzer))
+          return false;
+        p->SetToFilePathRange(path, offset, length, modification_time);
+        return true;
+      }
+      case storage::DataElement::Type::TYPE_BLOB: {
+        std::string uuid;
+        uint64 offset;
+        uint64 length;
+        if (!FuzzParam(&uuid, fuzzer))
+          return false;
+        if (!FuzzParam(&offset, fuzzer))
+          return false;
+        if (!FuzzParam(&length, fuzzer))
+          return false;
+        p->SetToBlobRange(uuid, offset, length);
+        return true;
+      }
+      case storage::DataElement::Type::TYPE_FILE_FILESYSTEM: {
+        GURL url;
+        uint64 offset;
+        uint64 length;
+        base::Time modification_time;
+        if (!FuzzParam(&url, fuzzer))
+          return false;
+        if (!FuzzParam(&offset, fuzzer))
+          return false;
+        if (!FuzzParam(&length, fuzzer))
+          return false;
+        if (!FuzzParam(&modification_time, fuzzer))
+          return false;
+        p->SetToFileSystemUrlRange(url, offset, length, modification_time);
+        return true;
+      }
+      default: {
+        NOTREACHED();
+        return false;
+      }
+    }
+  }
+};
+
+template <>
+struct FuzzTraits<ui::LatencyInfo> {
+  static bool Fuzz(ui::LatencyInfo* p, Fuzzer* fuzzer) {
+    // TODO(inferno): Add param traits for |latency_components|.
+    p->input_coordinates_size = static_cast<uint32>(
+        RandInRange(ui::LatencyInfo::kMaxInputCoordinates + 1));
+    if (!FuzzParamArray(
+        &p->input_coordinates[0], p->input_coordinates_size, fuzzer))
+      return false;
+    if (!FuzzParam(&p->trace_id, fuzzer))
+      return false;
+    if (!FuzzParam(&p->terminated, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<ui::LatencyInfo::InputCoordinate> {
+  static bool Fuzz(
+      ui::LatencyInfo::InputCoordinate* p, Fuzzer* fuzzer) {
+    if (!FuzzParam(&p->x, fuzzer))
+      return false;
+    if (!FuzzParam(&p->y, fuzzer))
+      return false;
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<url::Origin> {
+  static bool Fuzz(url::Origin* p, Fuzzer* fuzzer) {
+    std::string origin = p->string();
+    if (!FuzzParam(&origin, fuzzer))
+        return false;
+    *p = url::Origin(origin);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<URLPattern> {
+  static bool Fuzz(URLPattern* p, Fuzzer* fuzzer) {
+    int valid_schemes = p->valid_schemes();
+    std::string host = p->host();
+    std::string port = p->port();
+    std::string path = p->path();
+    if (!FuzzParam(&valid_schemes, fuzzer))
+      return false;
+    if (!FuzzParam(&host, fuzzer))
+      return false;
+    if (!FuzzParam(&port, fuzzer))
+      return false;
+    if (!FuzzParam(&path, fuzzer))
+      return false;
+    *p = URLPattern(valid_schemes);
+    p->SetHost(host);
+    p->SetPort(port);
+    p->SetPath(path);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<webrtc::DesktopSize> {
+  static bool Fuzz(webrtc::DesktopSize* p, Fuzzer* fuzzer) {
+    int32_t width = p->width();
+    int32_t height = p->height();
+    if (!FuzzParam(&width, fuzzer))
+      return false;
+    if (!FuzzParam(&height, fuzzer))
+      return false;
+    *p = webrtc::DesktopSize(width, height);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<webrtc::DesktopVector> {
+  static bool Fuzz(webrtc::DesktopVector* p, Fuzzer* fuzzer) {
+    int32_t x = p->x();
+    int32_t y = p->y();
+    if (!FuzzParam(&x, fuzzer))
+      return false;
+    if (!FuzzParam(&y, fuzzer))
+      return false;
+    p->set(x, y);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<webrtc::DesktopRect> {
+  static bool Fuzz(webrtc::DesktopRect* p, Fuzzer* fuzzer) {
+    int32_t left = p->left();
+    int32_t top = p->top();
+    int32_t right = p->right();
+    int32_t bottom = p->bottom();
+    if (!FuzzParam(&left, fuzzer))
+      return false;
+    if (!FuzzParam(&top, fuzzer))
+      return false;
+    if (!FuzzParam(&right, fuzzer))
+      return false;
+    if (!FuzzParam(&bottom, fuzzer))
+      return false;
+    *p = webrtc::DesktopRect::MakeLTRB(left, top, right, bottom);
+    return true;
+  }
+};
+
+template <>
+struct FuzzTraits<webrtc::MouseCursor> {
+  static bool Fuzz(webrtc::MouseCursor* p, Fuzzer* fuzzer) {
+    // TODO(mbarbella): Support mutation.
+    if (!fuzzer->ShouldGenerate())
+      return true;
+
+    webrtc::DesktopVector hotspot;
+    if (!FuzzParam(&hotspot, fuzzer))
+      return false;
+    // Using a small size here to avoid OOM or overflow on image allocation.
+    webrtc::DesktopSize size(RandInRange(100), RandInRange(100));
+    p->set_image(new webrtc::BasicDesktopFrame(size));
+    p->set_hotspot(hotspot);
+    return true;
+  }
+};
+
+// Redefine macros to generate generating from traits declarations.
+// STRUCT declarations cause corresponding STRUCT_TRAITS declarations to occur.
+#undef IPC_STRUCT_BEGIN
+#undef IPC_STRUCT_BEGIN_WITH_PARENT
+#undef IPC_STRUCT_MEMBER
+#undef IPC_STRUCT_END
+#define IPC_STRUCT_BEGIN_WITH_PARENT(struct_name, parent) \
+  IPC_STRUCT_BEGIN(struct_name)
+#define IPC_STRUCT_BEGIN(struct_name) IPC_STRUCT_TRAITS_BEGIN(struct_name)
+#define IPC_STRUCT_MEMBER(type, name, ...) IPC_STRUCT_TRAITS_MEMBER(name)
+#define IPC_STRUCT_END() IPC_STRUCT_TRAITS_END()
+
+// Set up so next include will generate generate trait classes.
+#undef IPC_STRUCT_TRAITS_BEGIN
+#undef IPC_STRUCT_TRAITS_MEMBER
+#undef IPC_STRUCT_TRAITS_PARENT
+#undef IPC_STRUCT_TRAITS_END
+#define IPC_STRUCT_TRAITS_BEGIN(struct_name) \
+  template <> \
+  struct FuzzTraits<struct_name> { \
+    static bool Fuzz(struct_name *p, Fuzzer* fuzzer) {
+
+#define IPC_STRUCT_TRAITS_MEMBER(name) \
+      if (!FuzzParam(&p->name, fuzzer)) \
+        return false;
+
+#define IPC_STRUCT_TRAITS_PARENT(type) \
+      if (!FuzzParam(static_cast<type*>(p), fuzzer)) \
+        return false;
+
+#define IPC_STRUCT_TRAITS_END() \
+      return true; \
+    } \
+  };
+
+// If |condition| isn't met, the messsge will fail to serialize. Try
+// increasingly smaller ranges until we find one that happens to meet
+// the condition, or fail trying.
+#undef IPC_ENUM_TRAITS_VALIDATE
+#define IPC_ENUM_TRAITS_VALIDATE(enum_name, condition)             \
+  template <>                                                      \
+  struct FuzzTraits<enum_name> {                                   \
+    static bool Fuzz(enum_name* p, Fuzzer* fuzzer) {               \
+      for (int shift = 30; shift; --shift) {                       \
+        for (int tries = 0; tries < 2; ++tries) {                  \
+          int value = RandInRange(1 << shift);                     \
+          if (condition) {                                         \
+            *reinterpret_cast<int*>(p) = value;                    \
+            return true;                                           \
+          }                                                        \
+        }                                                          \
+      }                                                            \
+      std::cerr << "failed to satisfy " << #condition << "\n";     \
+      return false;                                                \
+    }                                                              \
+  };
+
+// Bring them into existence.
+#include "tools/ipc_fuzzer/message_lib/all_messages.h"
+#include "ipc/ipc_message_null_macros.h"
+
+// Redefine macros to generate generating funtions
+#undef IPC_MESSAGE_DECL
+#define IPC_MESSAGE_DECL(kind, type, name, in, out, ilist, olist)       \
+  IPC_##kind##_##type##_FUZZ(name, in, out, ilist, olist)
+
+#define IPC_EMPTY_CONTROL_FUZZ(name, in, out, ilist, olist)             \
+  IPC::Message* fuzzer_for_##name(IPC::Message* msg, Fuzzer* fuzzer) {  \
+    if (msg) {                                                          \
+      return NULL;                                                      \
+    }                                                                   \
+    return new name();                                                  \
+  }
+
+#define IPC_EMPTY_ROUTED_FUZZ(name, in, out, ilist, olist)              \
+  IPC::Message* fuzzer_for_##name(IPC::Message* msg, Fuzzer* fuzzer) {  \
+    if (msg) {                                                          \
+      return NULL;                                                      \
+    }                                                                   \
+    return new name(RandInRange(MAX_FAKE_ROUTING_ID));                  \
+  }
+
+#define IPC_ASYNC_CONTROL_FUZZ(name, in, out, ilist, olist)             \
+  IPC::Message* fuzzer_for_##name(IPC::Message* msg, Fuzzer* fuzzer) {  \
+    IPC_TUPLE_IN_##in ilist p;                                          \
+    if (msg) {                                                          \
+      name::Read(static_cast<name*>(msg), &p);                          \
+    }                                                                   \
+    if (FuzzParam(&p, fuzzer)) {                                        \
+      return new name(IPC_MEMBERS_IN_##in(p));                          \
+    }                                                                   \
+    std::cerr << "Don't know how to handle " << #name << "\n";          \
+    return 0;                                                           \
+  }
+
+#define IPC_ASYNC_ROUTED_FUZZ(name, in, out, ilist, olist)              \
+  IPC::Message* fuzzer_for_##name(IPC::Message* msg, Fuzzer* fuzzer) {  \
+    IPC_TUPLE_IN_##in ilist p;                                          \
+    if (msg) {                                                          \
+      name::Read(static_cast<name*>(msg), &p);                          \
+    }                                                                   \
+    if (FuzzParam(&p, fuzzer)) {                                        \
+      return new name(RandInRange(MAX_FAKE_ROUTING_ID)                  \
+                      IPC_COMMA_##in                                    \
+                      IPC_MEMBERS_IN_##in(p));                          \
+    }                                                                   \
+    std::cerr << "Don't know how to handle " << #name << "\n";          \
+    return 0;                                                           \
+  }
+
+#define IPC_SYNC_CONTROL_FUZZ(name, in, out, ilist, olist)              \
+  IPC::Message* fuzzer_for_##name(IPC::Message* msg, Fuzzer* fuzzer) {  \
+    IPC_TUPLE_IN_##in ilist p;                                          \
+    if (msg) {                                                          \
+      name::ReadSendParam(static_cast<name*>(msg), &p);                 \
+    }                                                                   \
+    if (FuzzParam(&p, fuzzer)) {                                        \
+      return new name(IPC_MEMBERS_IN_##in(p)                            \
+                      IPC_COMMA_AND_##out(IPC_COMMA_##in)               \
+                      IPC_MEMBERS_OUT_##out());                         \
+    }                                                                   \
+    std::cerr << "Don't know how to handle " << #name << "\n";          \
+    return 0;                                                           \
+  }
+
+#define IPC_SYNC_ROUTED_FUZZ(name, in, out, ilist, olist)               \
+  IPC::Message* fuzzer_for_##name(IPC::Message* msg, Fuzzer* fuzzer) {  \
+    IPC_TUPLE_IN_##in ilist p;                                          \
+    if (msg) {                                                          \
+      name::ReadSendParam(static_cast<name*>(msg), &p);                 \
+    }                                                                   \
+    if (FuzzParam(&p, fuzzer)) {                                        \
+      return new name(RandInRange(MAX_FAKE_ROUTING_ID)                  \
+                      IPC_COMMA_OR_##out(IPC_COMMA_##in)                \
+                      IPC_MEMBERS_IN_##in(p)                            \
+                      IPC_COMMA_AND_##out(IPC_COMMA_##in)               \
+                      IPC_MEMBERS_OUT_##out());                         \
+    }                                                                   \
+    std::cerr << "Don't know how to handle " << #name << "\n";          \
+    return 0;                                                           \
+  }
+
+#define MAX_FAKE_ROUTING_ID 15
+
+#define IPC_MEMBERS_IN_0(p)
+#define IPC_MEMBERS_IN_1(p) get<0>(p)
+#define IPC_MEMBERS_IN_2(p) get<0>(p), get<1>(p)
+#define IPC_MEMBERS_IN_3(p) get<0>(p), get<1>(p), get<2>(p)
+#define IPC_MEMBERS_IN_4(p) get<0>(p), get<1>(p), get<2>(p), get<3>(p)
+#define IPC_MEMBERS_IN_5(p) get<0>(p), get<1>(p), get<2>(p), get<3>(p), \
+                            get<4>(p)
+
+#define IPC_MEMBERS_OUT_0()
+#define IPC_MEMBERS_OUT_1() NULL
+#define IPC_MEMBERS_OUT_2() NULL, NULL
+#define IPC_MEMBERS_OUT_3() NULL, NULL, NULL
+#define IPC_MEMBERS_OUT_4() NULL, NULL, NULL, NULL
+#define IPC_MEMBERS_OUT_5() NULL, NULL, NULL, NULL, NULL
+
+#include "tools/ipc_fuzzer/message_lib/all_messages.h"
+#include "ipc/ipc_message_null_macros.h"
+
+void PopulateFuzzerFunctionVector(
+    FuzzerFunctionVector* function_vector) {
+#undef IPC_MESSAGE_DECL
+#define IPC_MESSAGE_DECL(kind, type, name, in, out, ilist, olist) \
+  function_vector->push_back(fuzzer_for_##name);
+#include "tools/ipc_fuzzer/message_lib/all_messages.h"
+}
+
+// Redefine macros to register fuzzing functions into map.
+#include "ipc/ipc_message_null_macros.h"
+#undef IPC_MESSAGE_DECL
+#define IPC_MESSAGE_DECL(kind, type, name, in, out, ilist, olist) \
+  (*map)[static_cast<uint32>(name::ID)] = fuzzer_for_##name;
+
+void PopulateFuzzerFunctionMap(FuzzerFunctionMap* map) {
+#include "tools/ipc_fuzzer/message_lib/all_messages.h"
+}
+
+}  // namespace ipc_fuzzer