Move some Runtime:: functions and remove runtime.h as include when unnecessary.

src/runtime/runtime-strings.cc

Index: src/runtime/runtime-strings.cc
diff --git a/src/runtime/runtime-strings.cc b/src/runtime/runtime-strings.cc
index 1418a5fd5b10d792c624bd2e4e1c122b9c874187..ff683dce1e97ad634763b44952b81781b6a6d2c8 100644
--- a/src/runtime/runtime-strings.cc
+++ b/src/runtime/runtime-strings.cc
@@ -7,7 +7,6 @@
 #include "src/arguments.h"
 #include "src/jsregexp-inl.h"
 #include "src/jsregexp.h"
-#include "src/runtime/runtime.h"
 #include "src/runtime/runtime-utils.h"
 #include "src/runtime/string-builder.h"
 #include "src/string-search.h"
@@ -16,6 +15,47 @@ namespace v8 {
 namespace internal {
 
 
+// Perform string match of pattern on subject, starting at start index.
+// Caller must ensure that 0 <= start_index <= sub->length(),
+// and should check that pat->length() + start_index <= sub->length().
+int StringMatch(Isolate* isolate, Handle<String> sub, Handle<String> pat,
+                int start_index) {
+  DCHECK(0 <= start_index);
+  DCHECK(start_index <= sub->length());
+
+  int pattern_length = pat->length();
+  if (pattern_length == 0) return start_index;
+
+  int subject_length = sub->length();
+  if (start_index + pattern_length > subject_length) return -1;
+
+  sub = String::Flatten(sub);
+  pat = String::Flatten(pat);
+
+  DisallowHeapAllocation no_gc;  // ensure vectors stay valid
+  // Extract flattened substrings of cons strings before getting encoding.
+  String::FlatContent seq_sub = sub->GetFlatContent();
+  String::FlatContent seq_pat = pat->GetFlatContent();
+
+  // dispatch on type of strings
+  if (seq_pat.IsOneByte()) {
+    Vector<const uint8_t> pat_vector = seq_pat.ToOneByteVector();
+    if (seq_sub.IsOneByte()) {
+      return SearchString(isolate, seq_sub.ToOneByteVector(), pat_vector,
+                          start_index);
+    }
+    return SearchString(isolate, seq_sub.ToUC16Vector(), pat_vector,
+                        start_index);
+  }
+  Vector<const uc16> pat_vector = seq_pat.ToUC16Vector();
+  if (seq_sub.IsOneByte()) {
+    return SearchString(isolate, seq_sub.ToOneByteVector(), pat_vector,
+                        start_index);
+  }
+  return SearchString(isolate, seq_sub.ToUC16Vector(), pat_vector, start_index);
+}
+
+
 // This may return an empty MaybeHandle if an exception is thrown or
 // we abort due to reaching the recursion limit.
 MaybeHandle<String> StringReplaceOneCharWithString(
@@ -47,7 +87,7 @@ MaybeHandle<String> StringReplaceOneCharWithString(
 
     return subject;
   } else {
-    int index = Runtime::StringMatch(isolate, subject, search, 0);
+    int index = StringMatch(isolate, subject, search, 0);
     if (index == -1) return subject;
     *found = true;
     Handle<String> first = isolate->factory()->NewSubString(subject, 0, index);
@@ -101,7 +141,7 @@ RUNTIME_FUNCTION(Runtime_StringIndexOf) {
   if (!index->ToArrayIndex(&start_index)) return Smi::FromInt(-1);
 
   RUNTIME_ASSERT(start_index <= static_cast<uint32_t>(sub->length()));
-  int position = Runtime::StringMatch(isolate, sub, pat, start_index);
+  int position = StringMatch(isolate, sub, pat, start_index);
   return Smi::FromInt(position);
 }