A quick fix for Issue 18844 (Take 2).

This is the same change as <http://codereview.chromium.org/164309> that I reverted to investigate a test_shell_test failure (Issue 19263).

This change checks if the modifier flag is a WebInputEvent::MetaKey flag to
switch the scroll granularity when a user types a up/down key.
Editor::Commands ("MoveToBeginningOfDocument" and "MoveToEndOfDocument") works
only in an editable control, such as <textarea>. On the other hand, this
WebViewImpl::ScrollViewWithKeyboard() is for scrolling a page.

BUG=18844 "Apple (command) key + down arrow is not working"
TEST=Type command+down keys in a web page which contains a scroll bar, and
verify Chrome scrolls the page to its end.
Review URL: http://codereview.chromium.org/165523

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@23540 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 22 insertions, 4 deletions

diff --git a/webkit/glue/webview_impl.cc b/webkit/glue/webview_impl.cc
index 0b66f06..e94baac 100644
--- a/webkit/glue/webview_impl.cc
+++ b/webkit/glue/webview_impl.cc
@@ -811,7 +811,7 @@ bool WebViewImpl::KeyEventDefault(const WebKeyboardEvent& event) {
       if (event.windowsKeyCode == VKEY_SPACE) {
         int key_code = ((event.modifiers & WebInputEvent::ShiftKey) ?
                          VKEY_PRIOR : VKEY_NEXT);
-        return ScrollViewWithKeyboard(key_code);
+        return ScrollViewWithKeyboard(key_code, event.modifiers);
       }
       break;
     }
@@ -838,7 +838,7 @@ bool WebViewImpl::KeyEventDefault(const WebKeyboardEvent& event) {
         }
       }
       if (!event.isSystemKey) {
-        return ScrollViewWithKeyboard(event.windowsKeyCode);
+        return ScrollViewWithKeyboard(event.windowsKeyCode, event.modifiers);
       }
       break;
     }
@@ -849,7 +849,7 @@ bool WebViewImpl::KeyEventDefault(const WebKeyboardEvent& event) {
   return false;
 }
 
-bool WebViewImpl::ScrollViewWithKeyboard(int key_code) {
+bool WebViewImpl::ScrollViewWithKeyboard(int key_code, int modifiers) {
   Frame* frame = GetFocusedWebCoreFrame();
   if (!frame)
     return false;
@@ -868,11 +868,29 @@ bool WebViewImpl::ScrollViewWithKeyboard(int key_code) {
       break;
     case VKEY_UP:
       scroll_direction = ScrollUp;
+#if defined(OS_MACOSX)
+      // Many Mac applications (such as TextEdit, Safari, Firefox, etc.) scroll
+      // to the beginning of a page when typing command+up keys. It is better
+      // for Mac Chrome to emulate this behavior to improve compatibility with
+      // these applications.
+      scroll_granularity = (modifiers == WebInputEvent::MetaKey) ?
+          ScrollByDocument : ScrollByLine;
+#else
       scroll_granularity = ScrollByLine;
+#endif
       break;
     case VKEY_DOWN:
       scroll_direction = ScrollDown;
+#if defined(OS_MACOSX)
+      // Many Mac applications (such as TextEdit, Safari, Firefox, etc.) scroll
+      // to the end of a page when typing command+down keys. It is better
+      // for Mac Chrome to emulate this behavior to improve compatibility with
+      // these applications.
+      scroll_granularity = (modifiers == WebInputEvent::MetaKey) ?
+          ScrollByDocument : ScrollByLine;
+#else
       scroll_granularity = ScrollByLine;
+#endif
       break;
     case VKEY_HOME:
       scroll_direction = ScrollUp;
diff --git a/webkit/glue/webview_impl.h b/webkit/glue/webview_impl.h
index 275faed..17b139b 100644
--- a/webkit/glue/webview_impl.h
+++ b/webkit/glue/webview_impl.h
@@ -282,7 +282,7 @@ class WebViewImpl : public WebView, public base::RefCounted<WebViewImpl> {
   void RefreshAutofillPopup();
 
   // Returns true if the view was scrolled.
-  bool ScrollViewWithKeyboard(int key_code);
+  bool ScrollViewWithKeyboard(int key_code, int modifiers);
 
   // Removes fetcher from the set of pending image fetchers and deletes it.
   // This is invoked after the download is completed (or fails).