Convert components/tracing from static lib to component

This is a prerequisite for https://crrev.com/1292583002.

BUG=518823

Review URL: https://codereview.chromium.org/1298683002

Cr-Commit-Position: refs/heads/master@{#343700}

6 files changed, 50 insertions, 5 deletions

diff --git a/components/tracing.gyp b/components/tracing.gyp
index 7857830..32b1bb7 100644
--- a/components/tracing.gyp
+++ b/components/tracing.gyp
@@ -14,7 +14,7 @@
   'targets' : [
     {
       'target_name': 'tracing',
-      'type': 'static_library',
+      'type': '<(component)',
       'dependencies': [
         '../base/base.gyp:base',
         '../ipc/ipc.gyp:ipc',
@@ -22,11 +22,15 @@
       'include_dirs': [
         '..',
       ],
+      'defines': [
+        'TRACING_IMPLEMENTATION=1',
+      ],
       'sources': [
         'tracing/child_memory_dump_manager_delegate_impl.cc',
         'tracing/child_memory_dump_manager_delegate_impl.h',
         'tracing/child_trace_message_filter.cc',
         'tracing/child_trace_message_filter.h',
+        'tracing/tracing_export.h',
         'tracing/startup_tracing.cc',
         'tracing/startup_tracing.h',
         'tracing/tracing_messages.cc',
diff --git a/components/tracing/BUILD.gn b/components/tracing/BUILD.gn
index 336f5cb..b3186d9 100644
--- a/components/tracing/BUILD.gn
+++ b/components/tracing/BUILD.gn
@@ -2,28 +2,34 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-source_set("tracing") {
+component("tracing") {
   sources = [
     "child_memory_dump_manager_delegate_impl.cc",
     "child_memory_dump_manager_delegate_impl.h",
     "child_trace_message_filter.cc",
     "child_trace_message_filter.h",
+    "tracing_export.h",
     "tracing_messages.cc",
     "tracing_messages.h",
   ]
 
+  defines = [ "TRACING_IMPLEMENTATION" ]
+
   deps = [
     "//base",
     "//ipc",
   ]
 }
 
-source_set("startup_tracing") {
+component("startup_tracing") {
   sources = [
     "startup_tracing.cc",
     "startup_tracing.h",
+    "tracing_export.h",
   ]
 
+  defines = [ "TRACING_IMPLEMENTATION" ]
+
   deps = [
     "//base",
   ]
diff --git a/components/tracing/child_trace_message_filter.h b/components/tracing/child_trace_message_filter.h
index 0686de5..06c276d 100644
--- a/components/tracing/child_trace_message_filter.h
+++ b/components/tracing/child_trace_message_filter.h
@@ -10,6 +10,7 @@
 #include "base/metrics/histogram.h"
 #include "base/time/time.h"
 #include "base/trace_event/memory_dump_request_args.h"
+#include "components/tracing/tracing_export.h"
 #include "ipc/message_filter.h"
 
 namespace base {
@@ -19,7 +20,7 @@ class SingleThreadTaskRunner;
 namespace tracing {
 
 // This class sends and receives trace messages on child processes.
-class ChildTraceMessageFilter : public IPC::MessageFilter {
+class TRACING_EXPORT ChildTraceMessageFilter : public IPC::MessageFilter {
  public:
   explicit ChildTraceMessageFilter(
       base::SingleThreadTaskRunner* ipc_task_runner);
diff --git a/components/tracing/startup_tracing.h b/components/tracing/startup_tracing.h
index ae68f6f..5d1c74d 100644
--- a/components/tracing/startup_tracing.h
+++ b/components/tracing/startup_tracing.h
@@ -5,13 +5,15 @@
 #ifndef COMPONENTS_TRACING_STARTUP_TRACING_H_
 #define COMPONENTS_TRACING_STARTUP_TRACING_H_
 
+#include "components/tracing/tracing_export.h"
+
 namespace tracing {
 
 // Enable startup tracing according to the trace config file. If the trace
 // config file does not exist, it will do nothing. This is designed to be used
 // by Telemetry. Telemetry will stop tracing via DevTools later. To avoid
 // conflict, this should not be used when --trace-startup is enabled.
-void EnableStartupTracingIfConfigFileExists();
+void TRACING_EXPORT EnableStartupTracingIfConfigFileExists();
 
 }  // namespace tracing
 
diff --git a/components/tracing/tracing_export.h b/components/tracing/tracing_export.h
new file mode 100644
index 0000000..ac24e30
--- /dev/null
+++ b/components/tracing/tracing_export.h
@@ -0,0 +1,29 @@
+// 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.
+
+#ifndef COMPONENTS_TRACING_TRACING_EXPORT_H_
+#define COMPONENTS_TRACING_TRACING_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(TRACING_IMPLEMENTATION)
+#define TRACING_EXPORT __declspec(dllexport)
+#else
+#define TRACING_EXPORT __declspec(dllimport)
+#endif  // defined(TRACING_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(TRACING_IMPLEMENTATION)
+#define TRACING_EXPORT __attribute__((visibility("default")))
+#else
+#define TRACING_EXPORT
+#endif // defined(TRACING_IMPLEMENTATION)
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define TRACING_EXPORT
+#endif
+
+#endif  // COMPONENTS_TRACING_TRACING_EXPORT_H_
diff --git a/components/tracing/tracing_messages.h b/components/tracing/tracing_messages.h
index 7b24442..b14254e 100644
--- a/components/tracing/tracing_messages.h
+++ b/components/tracing/tracing_messages.h
@@ -11,11 +11,14 @@
 #include "base/sync_socket.h"
 #include "base/trace_event/memory_dump_request_args.h"
 #include "base/trace_event/trace_event_impl.h"
+#include "components/tracing/tracing_export.h"
 #include "ipc/ipc_channel_handle.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
 #include "ipc/ipc_platform_file.h"
 
+#undef IPC_MESSAGE_EXPORT
+#define IPC_MESSAGE_EXPORT TRACING_EXPORT
 #define IPC_MESSAGE_START TracingMsgStart
 
 IPC_STRUCT_TRAITS_BEGIN(base::trace_event::TraceLogStatus)