Implement SkImageFilter support in the compositor.

cc/gl_renderer.cc

Index: cc/gl_renderer.cc
diff --git a/cc/gl_renderer.cc b/cc/gl_renderer.cc
index 51d46f529c64d1b54f178b43885f25f410e805b4..192f0df0ae769559e7f0d5e39351174d02d7fee1 100644
--- a/cc/gl_renderer.cc
+++ b/cc/gl_renderer.cc
@@ -9,8 +9,11 @@
 #include "CCDamageTracker.h"
 #include "CCLayerQuad.h"
 #include "FloatQuad.h"
+#include "GrContext.h"
 #include "GrTexture.h"
 #include "NotImplemented.h"
+#include "SkGpuDevice.h"
+#include "SkGrTexturePixelRef.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/string_split.h"
@@ -349,6 +352,57 @@ static inline SkBitmap applyFilters(CCRendererGL* renderer, const WebKit::WebFil
     return source;
 }
 
+static SkBitmap applyImageFilter(CCRendererGL* renderer, SkImageFilter* filter, CCScopedTexture* sourceTexture)
+{
+    if (!filter)
+        return SkBitmap();
+
+    WebGraphicsContext3D* context3d = CCProxy::hasImplThread() ? WebSharedGraphicsContext3D::compositorThreadContext() : WebSharedGraphicsContext3D::mainThreadContext();
+    GrContext* grContext = CCProxy::hasImplThread() ? WebSharedGraphicsContext3D::compositorThreadGrContext() : WebSharedGraphicsContext3D::mainThreadGrContext();
+
+    if (!context3d || !grContext)
+        return SkBitmap();
+
+    renderer->context()->flush();
+
+    CCResourceProvider::ScopedWriteLockGL lock(renderer->resourceProvider(), sourceTexture->id());
+
+    // Wrap the source texture in a Ganesh platform texture.
+    GrPlatformTextureDesc platformTextureDescription;
+    platformTextureDescription.fWidth = sourceTexture->size().width();
+    platformTextureDescription.fHeight = sourceTexture->size().height();
+    platformTextureDescription.fConfig = kSkia8888_GrPixelConfig;
+    platformTextureDescription.fTextureHandle = lock.textureId();
+    SkAutoTUnref<GrTexture> texture(grContext->createPlatformTexture(platformTextureDescription));
+
+    // Place the platform texture inside an SkBitmap.
+    SkBitmap source;
+    source.setConfig(SkBitmap::kARGB_8888_Config, sourceTexture->size().width(), sourceTexture->size().height());
+    source.setPixelRef(new SkGrPixelRef(texture.get()))->unref();
+    
+    // Create a scratch texture for backing store.
+    GrTextureDesc desc;
+    desc.fFlags = kRenderTarget_GrTextureFlagBit | kNoStencil_GrTextureFlagBit;
+    desc.fSampleCnt = 0;
+    desc.fWidth = source.width();
+    desc.fHeight = source.height();
+    desc.fConfig = kSkia8888_GrPixelConfig;
+    GrAutoScratchTexture scratchTexture(grContext, desc, GrContext::kExact_ScratchTexMatch);
+
+    // Create a device and canvas using that backing store.
+    SkGpuDevice device(grContext, scratchTexture.detach());
+    SkCanvas canvas(&device);
+
+    // Draw the source bitmap through the filter to the canvas.
+    SkPaint paint;
+    paint.setImageFilter(filter);
+    canvas.clear(0x0);
+    canvas.drawSprite(source, 0, 0, &paint);
+    canvas.flush();
+    context3d->flush();
+    return device.accessBitmap(false);
+}
+
 scoped_ptr<CCScopedTexture> CCRendererGL::drawBackgroundFilters(DrawingFrame& frame, const CCRenderPassDrawQuad* quad, const WebKit::WebFilterOperations& filters, const WebTransformationMatrix& contentsDeviceTransform)
 {
     // This method draws a background filter, which applies a filter to any pixels behind the quad and seen through its background.
@@ -442,7 +496,12 @@ void CCRendererGL::drawRenderPassQuad(DrawingFrame& frame, const CCRenderPassDra
 
     // FIXME: Cache this value so that we don't have to do it for both the surface and its replica.
     // Apply filters to the contents texture.
-    SkBitmap filterBitmap = applyFilters(this, renderPass->filters(), contentsTexture);
+    SkBitmap filterBitmap;
+    if (renderPass->filter()) {
+        filterBitmap = applyImageFilter(this, renderPass->filter(), contentsTexture);
+    } else {
+        filterBitmap = applyFilters(this, renderPass->filters(), contentsTexture);
+    }
     scoped_ptr<CCResourceProvider::ScopedReadLockGL> contentsResourceLock;
     unsigned contentsTextureId = 0;
     if (filterBitmap.getTexture()) {