Rename some CJS / IJS names for clarity.

Prior cleanup before making FXJS/FXJSE share one v8 context.
Return CJS object rather than isolate in one place.
Use unique_ptr in one place.

Change-Id: I837ae4880368a6d72e59b38f37e06908e05c34bd
Reviewed-on: https://pdfium-review.googlesource.com/24950
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>
diff --git a/fpdfsdk/cpdfsdk_formfillenvironment.cpp b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
index 955c184..7ac7a0e 100644
--- a/fpdfsdk/cpdfsdk_formfillenvironment.cpp
+++ b/fpdfsdk/cpdfsdk_formfillenvironment.cpp
@@ -206,12 +206,12 @@
   m_pInfo->m_pJsPlatform->Doc_gotoPage(m_pInfo->m_pJsPlatform, nPageNum);
 }
 
-IJS_Runtime* CPDFSDK_FormFillEnvironment::GetJSRuntime() {
-  if (!IsJSInitiated())
+IJS_Runtime* CPDFSDK_FormFillEnvironment::GetIJSRuntime() {
+  if (!IsJSPlatformPresent())
     return nullptr;
-  if (!m_pJSRuntime)
-    m_pJSRuntime.reset(IJS_Runtime::Create(this));
-  return m_pJSRuntime.get();
+  if (!m_pIJSRuntime)
+    m_pIJSRuntime = IJS_Runtime::Create(this);
+  return m_pIJSRuntime.get();
 }
 
 CPDFSDK_AnnotHandlerMgr* CPDFSDK_FormFillEnvironment::GetAnnotHandlerMgr() {