Revert of Make disabling 2d canvas GPU acceleration for getImageData less aggressive.

third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp

Index: third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
diff --git a/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp b/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
index b1e788dadf5f83019e5716a571d01107c87b4678..2e38b192ed37b338fecca618ef940f34a33e00fa 100644
--- a/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
+++ b/third_party/WebKit/Source/platform/graphics/ImageBuffer.cpp
@@ -99,8 +99,6 @@
       m_snapshotState(InitialSnapshotState),
       m_surface(std::move(surface)),
       m_client(0),
-      m_gpuReadbackInvokedInCurrentFrame(false),
-      m_gpuReadbackSuccessiveFrames(0),
       m_gpuMemoryUsage(0) {
   m_surface->setImageBuffer(this);
   updateGPUMemoryUsage();
@@ -151,22 +149,6 @@
 }
 
 void ImageBuffer::finalizeFrame() {
-  if (isAccelerated() &&
-      ExpensiveCanvasHeuristicParameters::GPUReadbackForcesNoAcceleration &&
-      !RuntimeEnabledFeatures::canvas2dFixedRenderingModeEnabled()) {
-    if (m_gpuReadbackInvokedInCurrentFrame) {
-      m_gpuReadbackSuccessiveFrames++;
-      m_gpuReadbackInvokedInCurrentFrame = false;
-    } else {
-      m_gpuReadbackSuccessiveFrames = 0;
-    }
-
-    if (m_gpuReadbackSuccessiveFrames >=
-        ExpensiveCanvasHeuristicParameters::GPUReadbackMinSuccessiveFrames) {
-      disableAcceleration();
-    }
-  }
-
   m_surface->finalizeFrame();
 }
 
@@ -376,6 +358,11 @@
   }
 
   DCHECK(canvas());
+
+  if (ExpensiveCanvasHeuristicParameters::GetImageDataForcesNoAcceleration &&
+      !RuntimeEnabledFeatures::canvas2dFixedRenderingModeEnabled()) {
+    const_cast<ImageBuffer*>(this)->disableAcceleration();
+  }
 
   sk_sp<SkImage> snapshot = m_surface->newImageSnapshot(
       PreferNoAcceleration, SnapshotReasonGetImageData);
@@ -422,7 +409,6 @@
 
   snapshot->readPixels(info, result.data(), bytesPerPixel * rect.width(),
                        rect.x(), rect.y());
-  m_gpuReadbackInvokedInCurrentFrame = true;
 
   if (useF16Workaround) {
     uint32_t* pixel = (uint32_t*)result.data();