add UMA metrics for voice interaction entries.

chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc

Index: chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc
diff --git a/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc b/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc
index 97f746f60fc83e28d20ef544598de70092f3d14e..ef2c1d169f33433025ed67734f0d6be97ae48040 100644
--- a/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc
+++ b/chrome/browser/chromeos/arc/voice_interaction/arc_voice_interaction_framework_service.cc
@@ -15,6 +15,7 @@
 #include "base/containers/flat_set.h"
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
+#include "base/metrics/histogram_macros.h"
 #include "base/task_scheduler/post_task.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
@@ -122,6 +123,22 @@ void EncodeAndReturnImage(
       callback);
 }
 
+void RecordAcceleratorUmaMetrics(const ui::Accelerator& accelerator) {
+  if (accelerator.IsCmdDown() && accelerator.key_code() == ui::VKEY_A) {
+    if (accelerator.IsShiftDown()) {
+      UMA_HISTOGRAM_BOOLEAN("Keyboard.Shortcuts.CrosMetaLayerEntryMetaShiftA",
+                            true);
+      return;
+    }
+    UMA_HISTOGRAM_BOOLEAN("Keyboard.Shortcuts.CrosVoiceInteractionEntryMetaA",
+                          true);
+    return;
+  }
+  if (accelerator.IsCmdDown() && accelerator.key_code() == ui::VKEY_SPACE)

[Luis Héctor Chávez, 2017/05/23 15:24:44]

nit: you cannot elide braces since the body is not a single line.

[Muyuan, 2017/05/23 21:58:42]

Done.

+    UMA_HISTOGRAM_BOOLEAN(
+        "Keyboard.Shortcuts.CrosVoiceInteractionEntryMetaSpace", true);
+}
+
 }  // namespace
 
 // static
@@ -171,6 +188,8 @@ bool ArcVoiceInteractionFrameworkService::AcceleratorPressed(
     const ui::Accelerator& accelerator) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
+  RecordAcceleratorUmaMetrics(accelerator);
+
   if (accelerator.IsShiftDown()) {
     // Temporary, used for debugging.
     // Does not take into account or update the palette state.