Migrate TextDetector to use GC mojo wrappers.

No behavior change. This CL reduces potential risks of use-after-free bugs.

Bug: 1049056
Change-Id: I5e86464399de6553de95300992a7582ecf63eaf5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2132076Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Minoru Chikamune <chikamune@chromium.org>
Cr-Commit-Position: refs/heads/master@{#756081}

third_party/blink/renderer/modules/shapedetection/text_detector.cc

@@ -22,7 +22,7 @@ TextDetector* TextDetector::Create(ExecutionContext* context) {
   return MakeGarbageCollected<TextDetector>(context);
 }
 
-TextDetector::TextDetector(ExecutionContext* context) : ShapeDetector() {
+TextDetector::TextDetector(ExecutionContext* context) : text_service_(context) {
   // See https://bit.ly/2S0zRAS for task types.
   auto task_runner = context->GetTaskRunner(TaskType::kMiscPlatformAPI);
   context->GetBrowserInterfaceBroker().GetInterface(
@@ -35,7 +35,7 @@ TextDetector::TextDetector(ExecutionContext* context) : ShapeDetector() {
 ScriptPromise TextDetector::DoDetect(ScriptPromiseResolver* resolver,
                                      SkBitmap bitmap) {
   ScriptPromise promise = resolver->Promise();
-  if (!text_service_) {
+  if (!text_service_.is_bound()) {
     resolver->Reject(MakeGarbageCollected<DOMException>(
         DOMExceptionCode::kNotSupportedError,
         "Text detection service unavailable."));
@@ -90,6 +90,7 @@ void TextDetector::OnTextServiceConnectionError() {
 
 void TextDetector::Trace(Visitor* visitor) {
   ShapeDetector::Trace(visitor);
+  visitor->Trace(text_service_);
   visitor->Trace(text_service_requests_);
 }
 

third_party/blink/renderer/modules/shapedetection/text_detector.h

@@ -5,13 +5,14 @@
 #ifndef THIRD_PARTY_BLINK_RENDERER_MODULES_SHAPEDETECTION_TEXT_DETECTOR_H_
 #define THIRD_PARTY_BLINK_RENDERER_MODULES_SHAPEDETECTION_TEXT_DETECTOR_H_
 
-#include "mojo/public/cpp/bindings/remote.h"
 #include "services/shape_detection/public/mojom/textdetection.mojom-blink.h"
 #include "third_party/blink/renderer/bindings/core/v8/script_promise.h"
 #include "third_party/blink/renderer/bindings/core/v8/script_promise_resolver.h"
 #include "third_party/blink/renderer/modules/canvas/canvas2d/canvas_rendering_context_2d.h"
 #include "third_party/blink/renderer/modules/modules_export.h"
 #include "third_party/blink/renderer/modules/shapedetection/shape_detector.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_remote.h"
+#include "third_party/blink/renderer/platform/mojo/heap_mojo_wrapper_mode.h"
 
 namespace blink {
 
@@ -36,7 +37,9 @@ class MODULES_EXPORT TextDetector final : public ShapeDetector {
       Vector<shape_detection::mojom::blink::TextDetectionResultPtr>);
   void OnTextServiceConnectionError();
 
-  mojo::Remote<shape_detection::mojom::blink::TextDetection> text_service_;
+  HeapMojoRemote<shape_detection::mojom::blink::TextDetection,
+                 HeapMojoWrapperMode::kWithoutContextObserver>
+      text_service_;
 
   HeapHashSet<Member<ScriptPromiseResolver>> text_service_requests_;
 };