make some public DownloadItemImpl method private

These methods are never called by other classes, no need to mark them public.

Bug: 
Change-Id: I453e5831d60ac2970029c16fdd3011b012120695
Reviewed-on: https://chromium-review.googlesource.com/565963Reviewed-by: David Trainor <dtrainor@chromium.org>
Commit-Queue: Min Qin <qinmin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#486142}

content/browser/download/download_item_impl.h

@@ -36,14 +36,6 @@ class CONTENT_EXPORT DownloadItemImpl
     : public DownloadItem,
       public DownloadDestinationObserver {
  public:
-  enum ResumeMode {
-    RESUME_MODE_INVALID = 0,
-    RESUME_MODE_IMMEDIATE_CONTINUE,
-    RESUME_MODE_IMMEDIATE_RESTART,
-    RESUME_MODE_USER_CONTINUE,
-    RESUME_MODE_USER_RESTART
-  };
-
   // Information about the initial request that triggers the download. Most of
   // the fields are immutable after the DownloadItem is successfully created.
   // However, it is possible that the url chain is changed when resuming an
@@ -290,11 +282,6 @@ class CONTENT_EXPORT DownloadItemImpl
   // All remaining public interfaces virtual to allow for DownloadItemImpl
   // mocks.
 
-  // Determines the resume mode for an interrupted download. Requires
-  // last_reason_ to be set, but doesn't require the download to be in
-  // INTERRUPTED state.
-  virtual ResumeMode GetResumeMode() const;
-
   // State transition operations on regular downloads --------------------------
 
   // Start the download.
@@ -313,9 +300,6 @@ class CONTENT_EXPORT DownloadItemImpl
   // TODO(rdsmith): Unwind DownloadManagerImpl and DownloadItemImpl,
   // removing these from the public interface.
 
-  // Notify observers that this item is being removed by the user.
-  virtual void NotifyRemoved();
-
   virtual void OnDownloadedFileRemoved();
 
   // Provide a weak pointer reference to a DownloadDestinationObserver
@@ -613,6 +597,22 @@ class CONTENT_EXPORT DownloadItemImpl
   virtual void UpdateValidatorsOnResumption(
       const DownloadCreateInfo& new_create_info);
 
+  // Notify observers that this item is being removed by the user.
+  void NotifyRemoved();
+
+  enum ResumeMode {
+    RESUME_MODE_INVALID = 0,
+    RESUME_MODE_IMMEDIATE_CONTINUE,
+    RESUME_MODE_IMMEDIATE_RESTART,
+    RESUME_MODE_USER_CONTINUE,
+    RESUME_MODE_USER_RESTART
+  };
+
+  // Determines the resume mode for an interrupted download. Requires
+  // last_reason_ to be set, but doesn't require the download to be in
+  // INTERRUPTED state.
+  ResumeMode GetResumeMode() const;
+
   static DownloadState InternalToExternalState(
       DownloadInternalState internal_state);
   static DownloadInternalState ExternalToInternalState(

content/browser/download/mock_download_item_impl.h

@@ -117,7 +117,6 @@ class MockDownloadItemImpl : public DownloadItemImpl {
   MOCK_CONST_METHOD0(GetWebContents, WebContents*());
   MOCK_CONST_METHOD0(GetFileNameToReportUser, base::FilePath());
   MOCK_METHOD1(SetDisplayName, void(const base::FilePath&));
-  MOCK_METHOD0(NotifyRemoved, void());
   // May be called when vlog is on.
   std::string DebugString(bool verbose) const override { return std::string(); }
 };