[stubs] Factor CSA::GrowElementsCapacity() out of existing code.

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index 3ce4f8b7f0c8e7b099a83fb99dbb9b5564420e40..8fb0b07d1e90a5af9c3da80b672775004a0973b8 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -366,11 +366,27 @@ class CodeStubAssembler : public compiler::CodeAssembler {
   compiler::Node* CalculateNewElementsCapacity(
       compiler::Node* old_capacity, ParameterMode mode = INTEGER_PARAMETERS);
 
-  compiler::Node* CheckAndGrowElementsCapacity(compiler::Node* context,
-                                               compiler::Node* elements,
-                                               ElementsKind kind,
-                                               compiler::Node* key,
-                                               Label* fail);
+  // Tries to grow the |elements| array of given |object| to store the |key|
+  // or bails out if the growing gap is too big.

[Jakob Kummerow, 2016/09/09 10:49:35]

nit: add "Returns the new elements." here and below.

+  compiler::Node* TryGrowElementsCapacity(compiler::Node* object,
+                                          compiler::Node* elements,
+                                          ElementsKind kind,
+                                          compiler::Node* key, Label* bailout);
+
+  // Tries to grow the |capacity|-length |elements| array of given |object|
+  // to store the |key| or bails out if the growing gap is too big.
+  compiler::Node* TryGrowElementsCapacity(compiler::Node* object,
+                                          compiler::Node* elements,
+                                          ElementsKind kind,
+                                          compiler::Node* key,
+                                          compiler::Node* capacity,
+                                          ParameterMode mode, Label* bailout);
+
+  // Grows elements capacity of given object. Returns new elements.
+  compiler::Node* GrowElementsCapacity(
+      compiler::Node* object, compiler::Node* elements, ElementsKind from_kind,
+      ElementsKind to_kind, compiler::Node* capacity,
+      compiler::Node* new_capacity, ParameterMode mode, Label* bailout);
 
   // Allocation site manipulation
   void InitializeAllocationMemento(compiler::Node* base_allocation,