Add ANGLE platform tracing methods.

ui/gl/angle_platform_impl.h

 // 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 UI_GL_ANGLE_PLATFORM_IMPL_H_
 #define UI_GL_ANGLE_PLATFORM_IMPL_H_
 
 // Implements the ANGLE platform interface, for functionality like
 // histograms and trace profiling.
 
 #include "base/macros.h"
 #include "third_party/angle/include/platform/Platform.h"
 
 namespace gfx {
 
 // Derives the base ANGLE platform and provides implementations
 class ANGLEPlatformImpl : public angle::Platform {
  public:
   ANGLEPlatformImpl();
   ~ANGLEPlatformImpl() override;
 
   // angle::Platform:
+  double monotonicallyIncreasingTime() override;
+  const unsigned char* getTraceCategoryEnabledFlag(
+      const char* category_group) override;
+  TraceEventHandle addTraceEvent(char phase,
+                                 const unsigned char* category_group_enabled,
+                                 const char* name,
+                                 unsigned long long id,
+                                 double timestamp,
+                                 int num_args,
+                                 const char** arg_names,
+                                 const unsigned char* arg_types,
+                                 const unsigned long long* arg_values,
+                                 unsigned char flags) override;
+  void updateTraceEventDuration(const unsigned char* category_group_enabled,
+                                const char* name,
+                                TraceEventHandle handle) override;
   void histogramCustomCounts(const char* name,
                              int sample,
                              int min,
                              int max,
                              int bucket_count) override;
   void histogramEnumeration(const char* name,
                             int sample,
                             int boundary_value) override;
   void histogramSparse(const char* name, int sample) override;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ANGLEPlatformImpl);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_ANGLE_PLATFORM_IMPL_H_