Make sure to trace WebInputMethodController.

This class contains GC pointers and should be traced. Due to
a bug in the GC plugin, this wasn't being enforced. This also
changes the class to be a part object to clarify lifetimes.

Bug: 724418
Change-Id: I46d037d7f5040bc942b6bdf54d8d8a134914134b
Reviewed-on: https://chromium-review.googlesource.com/509149Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Daniel Cheng <dcheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#473763}

third_party/WebKit/Source/web/WebInputMethodControllerImpl.cpp

@@ -26,21 +26,20 @@
 namespace blink {
 
 WebInputMethodControllerImpl::WebInputMethodControllerImpl(
-    WebLocalFrameImpl* web_local_frame)
-    : web_local_frame_(web_local_frame) {}
+    WebLocalFrameImpl& web_frame)
+    : web_frame_(&web_frame) {}
 
 WebInputMethodControllerImpl::~WebInputMethodControllerImpl() {}
 
 // static
 WebInputMethodControllerImpl* WebInputMethodControllerImpl::FromFrame(
     LocalFrame* frame) {
-  WebLocalFrameImpl* web_local_frame_impl = WebLocalFrameImpl::FromFrame(frame);
-  return web_local_frame_impl ? web_local_frame_impl->GetInputMethodController()
-                              : nullptr;
+  WebLocalFrameImpl* web_frame_impl = WebLocalFrameImpl::FromFrame(frame);
+  return web_frame_impl ? web_frame_impl->GetInputMethodController() : nullptr;
 }
 
 DEFINE_TRACE(WebInputMethodControllerImpl) {
-  visitor->Trace(web_local_frame_);
+  visitor->Trace(web_frame_);
 }
 
 bool WebInputMethodControllerImpl::SetComposition(
@@ -62,7 +61,7 @@ bool WebInputMethodControllerImpl::SetComposition(
 
   // Select the range to be replaced with the composition later.
   if (!replacement_range.IsNull())
-    web_local_frame_->SelectRange(replacement_range);
+    web_frame_->SelectRange(replacement_range);
 
   // We should verify the parent node of this IME composition node are
   // editable because JavaScript may delete a parent node of the composition
@@ -128,7 +127,7 @@ bool WebInputMethodControllerImpl::CommitText(
 
   // Select the range to be replaced with the composition later.
   if (!replacement_range.IsNull())
-    web_local_frame_->SelectRange(replacement_range);
+    web_frame_->SelectRange(replacement_range);
 
   // TODO(editing-dev): The use of updateStyleAndLayoutIgnorePendingStylesheets
   // needs to be audited.  See http://crbug.com/590369 for more details.
@@ -148,7 +147,7 @@ WebTextInputType WebInputMethodControllerImpl::TextInputType() {
 }
 
 LocalFrame* WebInputMethodControllerImpl::GetFrame() const {
-  return web_local_frame_->GetFrame();
+  return web_frame_->GetFrame();
 }
 
 InputMethodController& WebInputMethodControllerImpl::GetInputMethodController()

third_party/WebKit/Source/web/WebInputMethodControllerImpl.h

@@ -6,6 +6,7 @@
 #define WebInputMethodControllerImpl_h
 
 #include "platform/heap/Handle.h"
+#include "platform/wtf/Allocator.h"
 #include "public/web/WebCompositionUnderline.h"
 #include "public/web/WebInputMethodController.h"
 
@@ -20,9 +21,10 @@ class WebString;
 
 class WebInputMethodControllerImpl : public WebInputMethodController {
   WTF_MAKE_NONCOPYABLE(WebInputMethodControllerImpl);
+  DISALLOW_NEW();
 
  public:
-  explicit WebInputMethodControllerImpl(WebLocalFrameImpl* owner_frame);
+  explicit WebInputMethodControllerImpl(WebLocalFrameImpl& web_frame);
   ~WebInputMethodControllerImpl() override;
 
   static WebInputMethodControllerImpl* FromFrame(LocalFrame*);
@@ -49,7 +51,7 @@ class WebInputMethodControllerImpl : public WebInputMethodController {
   InputMethodController& GetInputMethodController() const;
   WebPlugin* FocusedPluginIfInputMethodSupported() const;
 
-  WeakMember<WebLocalFrameImpl> web_local_frame_;
+  const Member<WebLocalFrameImpl> web_frame_;
 };
 }  // namespace blink
 

third_party/WebKit/Source/web/WebLocalFrameImpl.cpp

@@ -1599,7 +1599,7 @@ WebLocalFrameImpl::WebLocalFrameImpl(
       interface_provider_(interface_provider),
       interface_registry_(interface_registry),
       web_dev_tools_frontend_(0),
-      input_method_controller_(new WebInputMethodControllerImpl(this)),
+      input_method_controller_(*this),
       text_checker_client_(new TextCheckerClientImpl(this)),
       self_keep_alive_(this) {
   DCHECK(client_);
@@ -1631,6 +1631,7 @@ DEFINE_TRACE(WebLocalFrameImpl) {
   visitor->Trace(text_finder_);
   visitor->Trace(print_context_);
   visitor->Trace(context_menu_node_);
+  visitor->Trace(input_method_controller_);
   visitor->Trace(text_checker_client_);
   WebLocalFrameBase::Trace(visitor);
   // TODO(slangley): Call this from WebLocalFrameBase, once WebFrame is in core.
@@ -2563,9 +2564,8 @@ base::SingleThreadTaskRunner* WebLocalFrameImpl::UnthrottledTaskRunner() {
       ->ToSingleThreadTaskRunner();
 }
 
-WebInputMethodControllerImpl* WebLocalFrameImpl::GetInputMethodController()
-    const {
-  return input_method_controller_.get();
+WebInputMethodControllerImpl* WebLocalFrameImpl::GetInputMethodController() {
+  return &input_method_controller_;
 }
 
 void WebLocalFrameImpl::ExtractSmartClipData(WebRect rect_in_viewport,

third_party/WebKit/Source/web/WebLocalFrameImpl.h

@@ -313,7 +313,7 @@ class WEB_EXPORT WebLocalFrameImpl final
   base::SingleThreadTaskRunner* TimerTaskRunner() override;
   base::SingleThreadTaskRunner* LoadingTaskRunner() override;
   base::SingleThreadTaskRunner* UnthrottledTaskRunner() override;
-  WebInputMethodControllerImpl* GetInputMethodController() const override;
+  WebInputMethodControllerImpl* GetInputMethodController() override;
 
   void ExtractSmartClipData(WebRect rect_in_viewport,
                             WebString& clip_text,
@@ -514,7 +514,7 @@ class WEB_EXPORT WebLocalFrameImpl final
 
   Member<Node> context_menu_node_;
 
-  std::unique_ptr<WebInputMethodControllerImpl> input_method_controller_;
+  WebInputMethodControllerImpl input_method_controller_;
 
   // Stores the TextCheckerClient to bridge SpellChecker and WebTextCheckClient.
   Member<TextCheckerClientImpl> text_checker_client_;

third_party/WebKit/public/web/WebLocalFrame.h

@@ -551,7 +551,7 @@ class WebLocalFrame : public WebFrame {
   virtual base::SingleThreadTaskRunner* UnthrottledTaskRunner() = 0;
 
   // Returns the WebInputMethodController associated with this local frame.
-  virtual WebInputMethodController* GetInputMethodController() const = 0;
+  virtual WebInputMethodController* GetInputMethodController() = 0;
 
   // Loading ------------------------------------------------------------------
   // Creates and returns a loader. This function can be called only when this