compositor-worker: Initialize CW machinery plumbing to compositor and fire CW rAF callbacks.

third_party/WebKit/Source/web/WebViewImpl.cpp

Index: third_party/WebKit/Source/web/WebViewImpl.cpp
diff --git a/third_party/WebKit/Source/web/WebViewImpl.cpp b/third_party/WebKit/Source/web/WebViewImpl.cpp
index 358c045533e74111a3bb3a10c57126db939e78cf..f9de83406b7f66453a2f5973a7bf2de182e5c71d 100644
--- a/third_party/WebKit/Source/web/WebViewImpl.cpp
+++ b/third_party/WebKit/Source/web/WebViewImpl.cpp
@@ -33,6 +33,7 @@
 #include "core/CSSValueKeywords.h"
 #include "core/HTMLNames.h"
 #include "core/InputTypeNames.h"
+#include "core/animation/CustomCompositorAnimationManager.h"
 #include "core/clipboard/DataObject.h"
 #include "core/dom/Document.h"
 #include "core/dom/Fullscreen.h"
@@ -107,12 +108,15 @@
 #include "platform/PlatformKeyboardEvent.h"
 #include "platform/PlatformMouseEvent.h"
 #include "platform/RuntimeEnabledFeatures.h"
+#include "platform/ThreadSafeFunctional.h"
 #include "platform/TraceEvent.h"
 #include "platform/UserGestureIndicator.h"
+#include "platform/WaitableEvent.h"
 #include "platform/exported/WebActiveGestureAnimation.h"
 #include "platform/fonts/FontCache.h"
 #include "platform/graphics/Color.h"
 #include "platform/graphics/CompositorFactory.h"
+#include "platform/graphics/CompositorMutatorClient.h"
 #include "platform/graphics/FirstPaintInvalidationTracking.h"
 #include "platform/graphics/GraphicsContext.h"
 #include "platform/graphics/Image.h"
@@ -152,6 +156,8 @@
 #include "public/web/WebViewClient.h"
 #include "public/web/WebWindowFeatures.h"
 #include "web/CompositionUnderlineVectorBuilder.h"
+#include "web/CompositorMutatorImpl.h"
+#include "web/CompositorProxyClientImpl.h"
 #include "web/ContextFeaturesClientImpl.h"
 #include "web/ContextMenuAllowedScope.h"
 #include "web/DatabaseClientImpl.h"
@@ -443,6 +449,7 @@ WebViewImpl::WebViewImpl(WebViewClient* client)
     , m_shouldDispatchFirstLayoutAfterFinishedLoading(false)
     , m_displayMode(WebDisplayModeBrowser)
     , m_elasticOverscroll(FloatSize())
+    , m_mutator(nullptr)
     , m_scheduler(adoptPtr(Platform::current()->currentThread()->scheduler()->createWebViewScheduler(this).release()))
 {
     Page::PageClients pageClients;
@@ -4545,6 +4552,34 @@ void WebViewImpl::forceNextDrawingBufferCreationToFail()
     DrawingBuffer::forceNextDrawingBufferCreationToFail();
 }
 
+void createCompositoMutatorClient(CompositorMutatorClient** ptr, WaitableEvent* doneEvent)

[jbroman, 2016/04/29 19:42:23]

nit/spelling: "createCompositorMutatorClient"

Also, you can take std::unique_ptr<CompositorMutatorClient>* here, which would
let you deduplicate variables below (mutatorClient, client).

Also, this should be file-local: either a static function or it should be in an
anonymous namespace.

[flackr, 2016/05/03 22:24:55]

Done.
That's weird, I had originally tried to do this and couldn't get it to compile
but I must have been missing something because it works now. Done.
Done.

+{
+    CompositorMutatorImpl* mutator = CompositorMutatorImpl::create();
+    *ptr = new CompositorMutatorClient(mutator, mutator->animationManager());
+    mutator->setClient(*ptr);
+    doneEvent->signal();
+}
+
+CompositorProxyClient* WebViewImpl::createCompositorProxyClient(double referenceMonotonicTime)
+{
+    if (!m_mutator) {
+        std::unique_ptr<CompositorMutatorClient> mutatorClient;
+        CompositorMutatorClient* client;
+        OwnPtr<WaitableEvent> doneEvent = adoptPtr(new WaitableEvent());

[jbroman, 2016/04/29 19:42:22]

No need for an extra layer of heap allocation here; I think you can just do:

WaitableEvent doneEvent;

[flackr, 2016/05/03 22:24:55]

Done, or should i say doneEvent.signal();

+        WebThread* compositorThread = Platform::current()->compositorThread();
+        if (compositorThread) {

[jbroman, 2016/04/29 19:42:22]

super-nit: you can combine these two lines:

if (WebThread* compositorThread = Platform::current()->compositorThread()) {

[flackr, 2016/05/03 22:24:55]

Done.

+            compositorThread->getWebTaskRunner()->postTask(BLINK_FROM_HERE, threadSafeBind(&createCompositoMutatorClient, AllowCrossThreadAccess(&client), AllowCrossThreadAccess(doneEvent.get())));
+        } else {
+            createCompositoMutatorClient(&client, doneEvent.get());
+        }
+        doneEvent->wait();

[jbroman, 2016/04/29 19:42:22]

I'm not thrilled about blocking between threads, but it sounds like this is the
path of least resistance right now.

[flackr, 2016/05/03 22:24:55]

Agreed, but we also need to make sure we only create one mutator, and if we
don't get the pointer back then we have to somehow get it from the compositor
thread. I know we've worked out how to do this with a callback but for now I'll
add a TODO to refactor this.

[jbroman, 2016/05/04 17:59:00]

Yeah, I'm happy with that resolution.

+        mutatorClient.reset(client);
+        m_mutator = static_cast<CompositorMutatorImpl*>(mutatorClient->mutator());
+        m_layerTreeView->setMutatorClient(std::move(mutatorClient));
+    }
+    return new CompositorProxyClientImpl(m_mutator, referenceMonotonicTime);
+}
+
 void WebViewImpl::updatePageOverlays()
 {
     if (m_pageColorOverlay)