Fix InputConnection.deleteSurroundingText()

third_party/WebKit/Source/core/editing/InputMethodController.cpp

Index: third_party/WebKit/Source/core/editing/InputMethodController.cpp
diff --git a/third_party/WebKit/Source/core/editing/InputMethodController.cpp b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
index e1d2f0fe18572803afa15c40bfe7af59a60e36ee..a5c08174873a4bac26db07ebf95a96528d0f4743 100644
--- a/third_party/WebKit/Source/core/editing/InputMethodController.cpp
+++ b/third_party/WebKit/Source/core/editing/InputMethodController.cpp
@@ -456,6 +456,40 @@ void InputMethodController::extendSelectionAndDelete(int before, int after)
     TypingCommand::deleteSelection(*frame().document());
 }
 
+void InputMethodController::deleteSurroundingText(int before, int after)
+{
+    if (!editor().canEdit())
+        return;
+    PlainTextRange selectionOffsets(getSelectionOffsets());
+    if (selectionOffsets.isNull())
+        return;
+
+    int selectionStart = static_cast<int>(selectionOffsets.start());
+    int selectionEnd = static_cast<int>(selectionOffsets.end());
+
+    if (before > 0) {
+        int deleteLength = std::min(selectionStart, before);
+        int leftStart = selectionStart - deleteLength;
+        int leftEnd = selectionStart;
+        if (!setSelectionOffsets(PlainTextRange(leftStart, leftEnd)))
+            return;
+        TypingCommand::deleteSelection(*frame().document());
+
+        selectionStart = leftStart;
+        selectionEnd = selectionEnd - deleteLength;
+    }
+
+    if (after > 0) {
+        int rightStart = selectionEnd;
+        int rightEnd = selectionEnd + after;
+        if (!setSelectionOffsets(PlainTextRange(rightStart, rightEnd)))
+            return;
+        TypingCommand::deleteSelection(*frame().document());
+    }
+
+    setSelectionOffsets(PlainTextRange(selectionStart, selectionEnd));
+}
+
 DEFINE_TRACE(InputMethodController)
 {
     visitor->trace(m_frame);