Avoid maybe-uninitialized gcc warning.

Source/core/dom/CharacterData.cpp

Index: Source/core/dom/CharacterData.cpp
diff --git a/Source/core/dom/CharacterData.cpp b/Source/core/dom/CharacterData.cpp
index 7b28b43dfd7f4b9c85ec2220a7cc31e2a04eaa1d..f93c0f7b9cae651e6261ded70792198d82fa583d 100644
--- a/Source/core/dom/CharacterData.cpp
+++ b/Source/core/dom/CharacterData.cpp
@@ -124,7 +124,7 @@ static bool validateOffsetCount(unsigned offset, unsigned count, unsigned length
 
 void CharacterData::deleteData(unsigned offset, unsigned count, ExceptionState& exceptionState, RecalcStyleBehavior recalcStyleBehavior)
 {
-    unsigned realCount;
+    unsigned realCount = 0;
     if (!validateOffsetCount(offset, count, length(), realCount, exceptionState))
         return;
 
@@ -138,7 +138,7 @@ void CharacterData::deleteData(unsigned offset, unsigned count, ExceptionState&
 
 void CharacterData::replaceData(unsigned offset, unsigned count, const String& data, ExceptionState& exceptionState)
 {
-    unsigned realCount;
+    unsigned realCount = 0;
     if (!validateOffsetCount(offset, count, length(), realCount, exceptionState))
         return;