[Android WebView] Implement the capture picture API.

android_webview/native/aw_contents.cc

Index: android_webview/native/aw_contents.cc
diff --git a/android_webview/native/aw_contents.cc b/android_webview/native/aw_contents.cc
index 8d7e53c9c984bbf520d0f3f3fdc852ab970bb04f..51c6b14fb5e5652ab0ea333a9acdf1f4881b36c2 100644
--- a/android_webview/native/aw_contents.cc
+++ b/android_webview/native/aw_contents.cc
@@ -37,11 +37,9 @@
 #include "content/public/common/ssl_status.h"
 #include "jni/AwContents_jni.h"
 #include "net/base/x509_certificate.h"
-#include "skia/ext/refptr.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkDevice.h"
-#include "third_party/skia/include/core/SkPicture.h"
 #include "ui/gfx/transform.h"
 #include "ui/gl/gl_bindings.h"
 
@@ -61,6 +59,8 @@ using base::android::ConvertJavaStringToUTF16;
 using base::android::ConvertJavaStringToUTF8;
 using base::android::ConvertUTF16ToJavaString;
 using base::android::ConvertUTF8ToJavaString;
+using base::android::GetClass;
+using base::android::GetFieldID;
 using base::android::JavaRef;
 using base::android::ScopedJavaGlobalRef;
 using base::android::ScopedJavaLocalRef;
@@ -122,6 +122,8 @@ AwContents::AwContents(JNIEnv* env,
       view_visible_(false),
       compositor_visible_(false),
       is_composite_pending_(false),
+      on_new_picture_enabled_(false),
+      on_new_picture_invalidation_only_(false),
       last_frame_context_(NULL) {
   RendererPictureMap::CreateInstance();
   android_webview::AwBrowserDependencyFactory* dependency_factory =
@@ -380,9 +382,11 @@ void AwContents::DrawGL(AwDrawGLInfo* draw_info) {
 }
 
 bool AwContents::DrawSW(JNIEnv* env, jobject obj, jobject java_canvas) {
-  skia::RefPtr<SkPicture> picture =
-      RendererPictureMap::GetInstance()->GetRendererPicture(
-          web_contents_->GetRoutingID());
+  // TODO(leandrogracia): once Ubercompositor is ready and we support software
+  // rendering mode, we should avoid this as much as we can, ideally always.
+  // This includes finding a proper replacement for onDraw calls in hardware
+  // mode with software canvases.
+  skia::RefPtr<SkPicture> picture = GetLastCapturedPicture();
   if (!picture)
     return false;
 
@@ -683,7 +687,11 @@ void AwContents::Invalidate() {
   if (obj.is_null())
     return;
 
-  Java_AwContents_invalidate(env, obj.obj());
+  if (view_visible_)
+    Java_AwContents_invalidate(env, obj.obj());
+
+  if (on_new_picture_enabled_ && on_new_picture_invalidation_only_)
+    Java_AwContents_onNewPicture(env, obj.obj(), 0, 0, 0);
 }
 
 void AwContents::SetCompositorVisibility(bool visible) {
@@ -835,14 +843,79 @@ jint AwContents::ReleasePopupWebContents(JNIEnv* env, jobject obj) {
   return reinterpret_cast<jint>(pending_contents_.release());
 }
 
+void AwContents::CapturePicture(JNIEnv* env,
+                                jobject obj,
+                                jobject picture_data) {
+  skia::RefPtr<SkPicture> picture = GetLastCapturedPicture();
+  ScopedJavaLocalRef<jclass> external_picture_class = GetClass(env,
+      "org/chromium/android_webview/AwContentsClient$ExternalPictureData");
+  env->SetIntField(picture_data,
+      GetFieldID(env, external_picture_class, "nativePicture", "I"),
+      reinterpret_cast<jint>(picture.get()));
+  env->SetIntField(picture_data,
+      GetFieldID(env, external_picture_class, "width", "I"),
+      picture ? picture->width() : 0);
+  env->SetIntField(picture_data,
+      GetFieldID(env, external_picture_class, "height", "I"),
+      picture ? picture->height() : 0);
+}
+
+void AwContents::EnableOnNewPicture(JNIEnv* env,
+                                    jobject obj,
+                                    jboolean enabled,
+                                    jboolean invalidation_only) {
+  on_new_picture_enabled_ = enabled;
+  on_new_picture_invalidation_only_ = invalidation_only;
+
+  // If onNewPicture is triggered only on invalidation do not capture
+  // pictures on every new frame.
+  if (on_new_picture_invalidation_only_)
+    return;
+
+  // TODO(leandrogracia): uncomment when sw rendering uses Ubercompositor.
+  // Until then we need the callback enabled for SW mode invalidation.
+  // render_view_host_ext_->EnableCapturePictureCallback(enabled);
+}
+
 void AwContents::OnPictureUpdated(int process_id, int render_view_id) {
   CHECK_EQ(web_contents_->GetRenderProcessHost()->GetID(), process_id);
   if (render_view_id != web_contents_->GetRoutingID())
     return;
 
+  // TODO(leandrogracia): this can be made unconditional once software rendering
+  // uses Ubercompositor. Until then this path is required for SW invalidations.
+  if (on_new_picture_enabled_ && !on_new_picture_invalidation_only_) {
+    JNIEnv* env = AttachCurrentThread();
+    ScopedJavaLocalRef<jobject> obj = java_ref_.get(env);
+    if (!obj.is_null()) {
+      skia::RefPtr<SkPicture> picture = GetLastCapturedPicture();
+      Java_AwContents_onNewPicture(env, obj.obj(),
+          reinterpret_cast<jint>(picture.get()),
+          picture ? picture->width() : 0,
+          picture ? picture->height() : 0);
+    }
+  }
+
   // TODO(leandrogracia): delete when sw rendering uses Ubercompositor.
   // Invalidation should be provided by the compositor only.
   Invalidate();
 }
 
+skia::RefPtr<SkPicture> AwContents::GetLastCapturedPicture() {
+  // Use the latest available picture if the listener callback is enabled.
+  skia::RefPtr<SkPicture> picture;
+  if (on_new_picture_enabled_)
+    picture = RendererPictureMap::GetInstance()->GetRendererPicture(
+        web_contents_->GetRoutingID());
+
+  // If not available or not in listener mode get it synchronously.
+  if (!picture) {
+    render_view_host_ext_->CapturePictureSync();
+    picture = RendererPictureMap::GetInstance()->GetRendererPicture(
+        web_contents_->GetRoutingID());
+  }
+
+  return picture;
+}
+
 }  // namespace android_webview