[Downloads UI] Add histograms for file extensions

chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryItemWrapper.java

Index: chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryItemWrapper.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryItemWrapper.java b/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryItemWrapper.java
index 08c96918c7abbdff85cd9074d95c71de09247081..cb53085c7bd48400973d9aa68c5fc4eb11816654 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryItemWrapper.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/download/ui/DownloadHistoryItemWrapper.java
@@ -19,9 +19,51 @@ import org.chromium.content_public.browser.DownloadState;
 import org.chromium.ui.widget.Toast;
 
 import java.io.File;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Locale;
+import java.util.Map;
 
 /** Wraps different classes that contain information about downloads. */
 public abstract class DownloadHistoryItemWrapper extends TimedItem {
+    public static final Integer FILE_EXTENSION_OTHER = 0;
+    public static final Integer FILE_EXTENSION_APK = 1;
+    public static final Integer FILE_EXTENSION_CSV = 2;
+    public static final Integer FILE_EXTENSION_DOC = 3;
+    public static final Integer FILE_EXTENSION_DOCX = 4;
+    public static final Integer FILE_EXTENSION_EXE = 5;
+    public static final Integer FILE_EXTENSION_PDF = 6;
+    public static final Integer FILE_EXTENSION_PPT = 7;
+    public static final Integer FILE_EXTENSION_PPTX = 8;
+    public static final Integer FILE_EXTENSION_PSD = 9;
+    public static final Integer FILE_EXTENSION_RTF = 10;
+    public static final Integer FILE_EXTENSION_TXT = 11;
+    public static final Integer FILE_EXTENSION_XLS = 12;
+    public static final Integer FILE_EXTENSION_XLSX = 13;
+    public static final Integer FILE_EXTENSION_ZIP = 14;
+    public static final Integer FILE_EXTENSION_BOUNDARY = 15;
+
+    private static final Map<String, Integer> EXTENSIONS_MAP;
+    static {
+        Map<String, Integer> extensions = new HashMap<>();
+        extensions.put("apk", FILE_EXTENSION_APK);
+        extensions.put("csv", FILE_EXTENSION_CSV);
+        extensions.put("doc", FILE_EXTENSION_DOC);
+        extensions.put("docx", FILE_EXTENSION_DOCX);
+        extensions.put("exe", FILE_EXTENSION_EXE);
+        extensions.put("pdf", FILE_EXTENSION_PDF);
+        extensions.put("ppt", FILE_EXTENSION_PPT);
+        extensions.put("pptx", FILE_EXTENSION_PPTX);
+        extensions.put("psd", FILE_EXTENSION_PSD);
+        extensions.put("rtf", FILE_EXTENSION_RTF);
+        extensions.put("txt", FILE_EXTENSION_TXT);
+        extensions.put("xls", FILE_EXTENSION_XLS);
+        extensions.put("xlsx", FILE_EXTENSION_XLSX);
+        extensions.put("zip", FILE_EXTENSION_ZIP);
+
+        EXTENSIONS_MAP = Collections.unmodifiableMap(extensions);
+    }
+
     protected final BackendProvider mBackendProvider;
     protected final ComponentName mComponentName;
     private Long mStableId;
@@ -68,6 +110,9 @@ public abstract class DownloadHistoryItemWrapper extends TimedItem {
     /** @return The mime type or null if the item doesn't have one. */
     public abstract String getMimeType();
 
+    /** @return The file extension type. See list at the top of the file. */
+    public abstract int getFileExtensionType();
+
     /** @return How much of the download has completed, or -1 if there is no progress. */
     public abstract int getDownloadProgress();
 
@@ -98,17 +143,30 @@ public abstract class DownloadHistoryItemWrapper extends TimedItem {
     protected void recordOpenSuccess() {
         RecordHistogram.recordEnumeratedHistogram("Android.DownloadManager.Item.OpenSucceeded",
                 getFilterType(), DownloadFilter.FILTER_BOUNDARY);
+
+        if (getFilterType() == DownloadFilter.FILTER_OTHER) {
+            RecordHistogram.recordEnumeratedHistogram(
+                    "Android.DownloadManager.OtherExtensions.OpenSucceeded",
+                    getFileExtensionType(), FILE_EXTENSION_BOUNDARY);
+        }
     }
 
     protected void recordOpenFailure() {
         RecordHistogram.recordEnumeratedHistogram("Android.DownloadManager.Item.OpenFailed",
                 getFilterType(), DownloadFilter.FILTER_BOUNDARY);
+
+        if (getFilterType() == DownloadFilter.FILTER_OTHER) {
+            RecordHistogram.recordEnumeratedHistogram(
+                    "Android.DownloadManager.OtherExtensions.OpenFailed",
+                    getFileExtensionType(), FILE_EXTENSION_BOUNDARY);
+        }
     }
 
     /** Wraps a {@link DownloadItem}. */
     public static class DownloadItemWrapper extends DownloadHistoryItemWrapper {
         private final DownloadItem mItem;
         private File mFile;
+        private Integer mFileExtensionType;
 
         DownloadItemWrapper(DownloadItem item, BackendProvider provider, ComponentName component) {
             super(provider, component);
@@ -171,6 +229,28 @@ public abstract class DownloadHistoryItemWrapper extends TimedItem {
         }
 
         @Override
+        public int getFileExtensionType() {
+            if (mFileExtensionType == null) {
+                int extensionIndex = getFilePath().lastIndexOf(".");
+                if (extensionIndex == -1 || extensionIndex == getFilePath().length() - 1) {
+                    mFileExtensionType = FILE_EXTENSION_OTHER;
+                    return mFileExtensionType;
+                }
+
+                String extension = getFilePath().substring(extensionIndex + 1);
+                if (!TextUtils.isEmpty(extension) && EXTENSIONS_MAP.containsKey(
+                        extension.toLowerCase(Locale.getDefault()))) {
+                    mFileExtensionType = EXTENSIONS_MAP.get(
+                            extension.toLowerCase(Locale.getDefault()));
+                } else {
+                    mFileExtensionType = FILE_EXTENSION_OTHER;
+                }
+            }
+
+            return mFileExtensionType;
+        }
+
+        @Override
         public int getDownloadProgress() {
             return mItem.getDownloadInfo().getPercentCompleted();
         }
@@ -284,6 +364,11 @@ public abstract class DownloadHistoryItemWrapper extends TimedItem {
         }
 
         @Override
+        public int getFileExtensionType() {
+            return FILE_EXTENSION_OTHER;
+        }
+
+        @Override
         public int getDownloadProgress() {
             return -1;
         }