Size reduction from moving const char arrays out of header

cc/debug/devtools_instrumentation.h

 // Copyright 2013 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 CC_DEBUG_DEVTOOLS_INSTRUMENTATION_H_
 #define CC_DEBUG_DEVTOOLS_INSTRUMENTATION_H_
 
 #include <stdint.h>
 
 #include <memory>
 
 #include "base/macros.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 
 namespace cc {
 namespace devtools_instrumentation {
 
 namespace internal {
-const char kCategory[] = TRACE_DISABLED_BY_DEFAULT("devtools.timeline");
-const char kCategoryFrame[] =
-    TRACE_DISABLED_BY_DEFAULT("devtools.timeline.frame");
-const char kData[] = "data";
-const char kFrameId[] = "frameId";
-const char kLayerId[] = "layerId";
-const char kLayerTreeId[] = "layerTreeId";
-const char kPixelRefId[] = "pixelRefId";
+extern const char kCategory[];
+extern const char kCategoryFrame[];
+extern const char kData[];
+extern const char kFrameId[];
+extern const char kLayerId[];
+extern const char kLayerTreeId[];
+extern const char kPixelRefId[];
 
-const char kImageDecodeTask[] = "ImageDecodeTask";
-const char kBeginFrame[] = "BeginFrame";
-const char kNeedsBeginFrameChanged[] = "NeedsBeginFrameChanged";
-const char kActivateLayerTree[] = "ActivateLayerTree";
-const char kRequestMainThreadFrame[] = "RequestMainThreadFrame";
-const char kBeginMainThreadFrame[] = "BeginMainThreadFrame";
-const char kDrawFrame[] = "DrawFrame";
-const char kCompositeLayers[] = "CompositeLayers";
+extern const char kImageDecodeTask[];
+extern const char kBeginFrame[];
+extern const char kNeedsBeginFrameChanged[];
+extern const char kActivateLayerTree[];
+extern const char kRequestMainThreadFrame[];
+extern const char kBeginMainThreadFrame[];
+extern const char kDrawFrame[];
+extern const char kCompositeLayers[];
 }  // namespace internal
 
-const char kPaintSetup[] = "PaintSetup";
-const char kUpdateLayer[] = "UpdateLayer";
+extern const char kPaintSetup[];
+extern const char kUpdateLayer[];
 
 class ScopedLayerTask {
  public:
   ScopedLayerTask(const char* event_name, int layer_id)
     : event_name_(event_name) {
     TRACE_EVENT_BEGIN1(internal::kCategory, event_name_,
         internal::kLayerId, layer_id);
   }
   ~ScopedLayerTask() {
     TRACE_EVENT_END0(internal::kCategory, event_name_);
@@ skipping 142 matching lines @@
   TRACE_EVENT_INSTANT2(
       internal::kCategoryFrame, internal::kNeedsBeginFrameChanged,
       TRACE_EVENT_SCOPE_THREAD, internal::kLayerTreeId, layer_tree_host_id,
       internal::kData, NeedsBeginFrameData(new_value));
 }
 
 }  // namespace devtools_instrumentation
 }  // namespace cc
 
 #endif  // CC_DEBUG_DEVTOOLS_INSTRUMENTATION_H_