ShapeDetection: support CanvasImageSource as detect() source

third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp

Index: third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
diff --git a/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp b/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
index 7ad81a6bf0ec83d632043f08af84645e0bd0a8a9..1e9adb673b4f8e6f8258bdf8232995f7d4196191 100644
--- a/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
+++ b/third_party/WebKit/Source/modules/shapedetection/FaceDetector.cpp
@@ -8,6 +8,7 @@
 #include "core/dom/DOMRect.h"
 #include "core/dom/Document.h"
 #include "core/fetch/ImageResource.h"
+#include "core/frame/ImageBitmap.h"
 #include "core/frame/LocalDOMWindow.h"
 #include "core/frame/LocalFrame.h"
 #include "core/html/HTMLImageElement.h"
@@ -20,7 +21,7 @@ namespace blink {
 
 namespace {
 
-mojo::ScopedSharedBufferHandle getSharedBufferHandle(
+mojo::ScopedSharedBufferHandle getSharedBufferHandleForImageElement(
     const HTMLImageElement* img,
     ScriptPromiseResolver* resolver) {
   ImageResource* const imageResource = img->cachedImage();
@@ -112,7 +113,7 @@ ScriptPromise FaceDetector::detect(ScriptState* scriptState,
   }
 
   mojo::ScopedSharedBufferHandle sharedBufferHandle =
-      getSharedBufferHandle(img, resolver);
+      getSharedBufferHandleForImageElement(img, resolver);
   if (!sharedBufferHandle->is_valid())
     return promise;
 
@@ -133,6 +134,75 @@ ScriptPromise FaceDetector::detect(ScriptState* scriptState,
   return promise;
 }
 
+ScriptPromise FaceDetector::detect(ScriptState* scriptState,
+                                   ImageBitmap* imageBitmap) {
+  ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
+  ScriptPromise promise = resolver->promise();
+
+  if (!imageBitmap) {
+    resolver->reject(
+        DOMException::create(InvalidStateError, "Invalid ImageBitmap"));
+    return promise;
+  }
+  DCHECK(imageBitmap->size().area()) << "ImageBitmap has invalid dimension(s).";
+  if (!imageBitmap->originClean()) {
+    resolver->reject(
+        DOMException::create(SecurityError, "ImageBitmap is not origin clean"));
+    return promise;
+  }
+
+  SkPixmap pixmap;
+  RefPtr<Uint8Array> pixelData;

[xianglu, 2016/10/25 21:07:45]

Consider moving this line above l.165.

[mcasas, 2016/10/25 21:47:38]

Can't move it in there, or it will fall out of scope
and invalidate the pixelData->data() referenced
in l.169.

+  uint8_t* pixelDataPtr = nullptr;
+  int allocationSize = 0;
+  // Use |skImage|'s pixels if it has direct access to them, otherwise retrieve
+  // them from elsewhere via copyBitmapData().
+  sk_sp<SkImage> skImage = imageBitmap->bitmapImage()->imageForCurrentFrame();
+  if (skImage->peekPixels(&pixmap)) {
+    pixelDataPtr = static_cast<uint8_t*>(pixmap.writable_addr());
+    allocationSize = pixmap.getSafeSize();
+  } else {
+    pixelData = imageBitmap->copyBitmapData(imageBitmap->isPremultiplied()
+                                                ? PremultiplyAlpha
+                                                : DontPremultiplyAlpha,
+                                            N32ColorType);
+    pixelDataPtr = pixelData->data();
+    allocationSize = imageBitmap->size().area() * 4;  // 4 bpp.
+  }
+  DCHECK(allocationSize);
+
+  mojo::ScopedSharedBufferHandle sharedBufferHandle =
+      mojo::SharedBufferHandle::Create(allocationSize);
+
+  if (!pixelDataPtr || !sharedBufferHandle->is_valid()) {
+    resolver->reject(
+        DOMException::create(InvalidStateError, "Internal allocation error"));
+    return promise;
+  }
+
+  if (!m_service) {
+    resolver->reject(DOMException::create(
+        NotFoundError, "Face detection service unavailable."));
+    return promise;
+  }
+
+  const mojo::ScopedSharedBufferMapping mappedBuffer =
+      sharedBufferHandle->Map(allocationSize);
+  DCHECK(mappedBuffer.get());
+
+  memcpy(mappedBuffer.get(), pixelDataPtr, allocationSize);
+
+  m_serviceRequests.add(resolver);
+  DCHECK(m_service.is_bound());
+  m_service->DetectFace(std::move(sharedBufferHandle), imageBitmap->width(),
+                        imageBitmap->height(),
+                        convertToBaseCallback(WTF::bind(
+                            &FaceDetector::onDetectFace, wrapPersistent(this),
+                            wrapPersistent(resolver))));
+  sharedBufferHandle.reset();
+  return promise;
+}
+
 void FaceDetector::onDetectFace(
     ScriptPromiseResolver* resolver,
     mojom::blink::FaceDetectionResultPtr faceDetectionResult) {