Improving direction-based selection strategy.

Source/core/editing/FrameSelection.cpp

 /*
  * Copyright (C) 2004, 2008, 2009, 2010 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 1920 matching lines @@
     if (m_granularityStrategy && m_granularityStrategy->GetType() == strategyType)
         return m_granularityStrategy.get();
 
     if (strategyType == SelectionStrategy::Direction)
         m_granularityStrategy = adoptPtr(new DirectionGranularityStrategy());
     else
         m_granularityStrategy = adoptPtr(new CharacterGranularityStrategy());
     return m_granularityStrategy.get();
 }
 
-void FrameSelection::moveRangeSelectionExtent(const VisiblePosition& extentPosition)
+void FrameSelection::moveRangeSelectionExtent(const IntPoint& contentsPoint)
 {
-    if (isNone() || m_selection.visibleBase() == extentPosition)
+    TRACE_EVENT0("blink", "FrameSelection::moveRangeSelectionExtent");
+    if (isNone())
         return;
 
-    VisibleSelection newSelection = granularityStrategy()->updateExtent(extentPosition, selection());
+    VisibleSelection newSelection = granularityStrategy()->updateExtent(contentsPoint, m_frame);
     setSelection(
         newSelection,
         FrameSelection::CloseTyping | FrameSelection::ClearTypingStyle | FrameSelection::DoNotClearStrategy | UserTriggered,
         FrameSelection::AlignCursorOnScrollIfNeeded,
         CharacterGranularity);
 }
 
 void FrameSelection::moveRangeSelection(const VisiblePosition& basePosition, const VisiblePosition& extentPosition, TextGranularity granularity)
 {
     VisibleSelection newSelection(basePosition, extentPosition);
@@ skipping 16 matching lines @@
 
 void showTree(const blink::FrameSelection* sel)
 {
     if (sel)
         sel->showTreeForThis();
     else
         fprintf(stderr, "Cannot showTree for (nil) FrameSelection.\n");
 }
 
 #endif