Move state machines to state_machines subdir

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

Index: third_party/WebKit/Source/core/editing/EditingUtilities.cpp
diff --git a/third_party/WebKit/Source/core/editing/EditingUtilities.cpp b/third_party/WebKit/Source/core/editing/EditingUtilities.cpp
index 3fe2471ade436bcc32bb056d46e8063e953f0e89..66b0fc31defe7dd0c0b8bb6fb73b455160e08039 100644
--- a/third_party/WebKit/Source/core/editing/EditingUtilities.cpp
+++ b/third_party/WebKit/Source/core/editing/EditingUtilities.cpp
@@ -32,6 +32,7 @@
 #include "core/dom/Range.h"
 #include "core/dom/Text.h"
 #include "core/dom/shadow/ShadowRoot.h"
+#include "core/editing/BackspaceStateMachine.h"
 #include "core/editing/EditingStrategy.h"
 #include "core/editing/Editor.h"
 #include "core/editing/PlainTextRange.h"
@@ -543,6 +544,35 @@ PositionInFlatTree lastEditablePositionBeforePositionInRoot(const PositionInFlat
     return lastEditablePositionBeforePositionInRootAlgorithm<EditingInFlatTreeStrategy>(position, highestRoot);
 }
 
+template<typename StateMachine>
+int findNextBoundaryOffset(const String& str, int current)
+{
+    constexpr typename StateMachine::State NeedMoreCodeUnit = StateMachine::State::NeedMoreCodeUnit;
+    constexpr typename StateMachine::State Finished = StateMachine::State::Finished;
+    constexpr typename StateMachine::State Unknown = StateMachine::State::Unknown;
+
+    StateMachine machine;
+    typename StateMachine::State state = Unknown;
+
+    for (int i = current - 1; i >= 0; --i) {
+        state = machine.feedPrecedingCodeUnit(str[i]);
+        DCHECK(state != Unknown);
+        if (state != NeedMoreCodeUnit)
+            break;
+    }
+    if (state == Finished)
+        return current + machine.finalizeAndGetBoundaryOffset();
+    const int length = str.length();
+    for (int i = current; i < length; ++i) {
+        state = machine.feedFollowingCodeUnit(str[i]);
+        DCHECK(state != Unknown);
+        if (state != NeedMoreCodeUnit)
+            break;
+    }
+    DCHECK(state != StateMachine::State::NeedFollowingCodeUnit);
+    return current + machine.finalizeAndGetBoundaryOffset();
+}
+
 int uncheckedPreviousOffset(const Node* node, int current)
 {
     if (!node->isTextNode())
@@ -567,11 +597,7 @@ static int uncheckedPreviousOffsetForBackwardDeletion(const Node* node, int curr
 
     const String& text = toText(node)->data();
     DCHECK(static_cast<unsigned>(current - 1) < text.length());
-    if (U16_IS_TRAIL(text[--current]))
-        --current;
-    if (current < 0)
-        current = 0;
-    return current;
+    return findNextBoundaryOffset<BackspaceStateMachine>(text, current);
 }
 
 int uncheckedNextOffset(const Node* node, int current)