Fixed crash in WebFrameImpl::resetMatchCount function.

Source/web/WebLocalFrameImpl.cpp

Index: Source/web/WebLocalFrameImpl.cpp
diff --git a/Source/web/WebLocalFrameImpl.cpp b/Source/web/WebLocalFrameImpl.cpp
index 0c9744fe66ec5ae744fa64b5993b62a5dcfe32f1..261013ec19761cdafde33bda14476a5821990078 100644
--- a/Source/web/WebLocalFrameImpl.cpp
+++ b/Source/web/WebLocalFrameImpl.cpp
@@ -1438,14 +1438,12 @@ void WebLocalFrameImpl::increaseMatchCount(int count, int identifier)
 {
     // This function should only be called on the mainframe.
     ASSERT(!parent());
-    ASSERT(m_textFinder);
-    m_textFinder->increaseMatchCount(identifier, count);
+    ensureTextFinder().increaseMatchCount(identifier, count);
 }
 
 void WebLocalFrameImpl::resetMatchCount()
 {
-    ASSERT(m_textFinder);
-    m_textFinder->resetMatchCount();
+    ensureTextFinder().resetMatchCount();
 }
 
 void WebLocalFrameImpl::sendOrientationChangeEvent()
@@ -1472,8 +1470,7 @@ int WebLocalFrameImpl::findMatchMarkersVersion() const
 int WebLocalFrameImpl::selectNearestFindMatch(const WebFloatPoint& point, WebRect* selectionRect)
 {
     ASSERT(!parent());
-    ASSERT(m_textFinder);
-    return m_textFinder->selectNearestFindMatch(point, selectionRect);
+    return ensureTextFinder().selectNearestFindMatch(point, selectionRect);
 }
 
 WebFloatRect WebLocalFrameImpl::activeFindMatchRect()
@@ -1488,8 +1485,7 @@ WebFloatRect WebLocalFrameImpl::activeFindMatchRect()
 void WebLocalFrameImpl::findMatchRects(WebVector<WebFloatRect>& outputRects)
 {
     ASSERT(!parent());
-    ASSERT(m_textFinder);
-    m_textFinder->findMatchRects(outputRects);
+    ensureTextFinder().findMatchRects(outputRects);
 }
 
 void WebLocalFrameImpl::setTickmarks(const WebVector<WebRect>& tickmarks)