Add ANGLE Platform implementation.

ui/gl/angle_platform_impl.cc

Index: ui/gl/angle_platform_impl.cc
diff --git a/ui/gl/angle_platform_impl.cc b/ui/gl/angle_platform_impl.cc
new file mode 100644
index 0000000000000000000000000000000000000000..2ce12b823afb36bb1a3f3cb46f7e3e4c7699822f
--- /dev/null
+++ b/ui/gl/angle_platform_impl.cc
@@ -0,0 +1,50 @@
+// 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 "ui/gl/angle_platform_impl.h"
+
+#include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
+
+namespace gfx {
+
+ANGLEPlatformImpl::ANGLEPlatformImpl() {
+}
+
+ANGLEPlatformImpl::~ANGLEPlatformImpl() {
+}
+
+void ANGLEPlatformImpl::histogramCustomCounts(const char* name,
+                                              int sample,
+                                              int min,
+                                              int max,
+                                              int bucket_count) {
+  // Copied from histogram macro, but without the static variable caching
+  // the histogram because name is dynamic.
+  base::HistogramBase* counter = base::Histogram::FactoryGet(
+      name, min, max, bucket_count,
+      base::HistogramBase::kUmaTargetedHistogramFlag);
+  DCHECK_EQ(name, counter->histogram_name());
+  counter->Add(sample);
+}
+
+void ANGLEPlatformImpl::histogramEnumeration(const char* name,
+                                             int sample,
+                                             int boundary_value) {
+  // Copied from histogram macro, but without the static variable caching
+  // the histogram because name is dynamic.
+  base::HistogramBase* counter = base::LinearHistogram::FactoryGet(
+      name, 1, boundary_value, boundary_value + 1,
+      base::HistogramBase::kUmaTargetedHistogramFlag);
+  DCHECK_EQ(name, counter->histogram_name());
+  counter->Add(sample);
+}
+
+void ANGLEPlatformImpl::histogramSparse(const char* name, int sample) {
+  // For sparse histograms, we can use the macro, as it does not incorporate a
+  // static.
+  UMA_HISTOGRAM_SPARSE_SLOWLY(name, sample);
+}
+
+}  // namespace gfx