Cleanup namespace usage in platform/graphics/[filters/* to skia/*] and platform/graphics/[B-D]*

Source/platform/graphics/Canvas2DLayerManager.cpp

Index: Source/platform/graphics/Canvas2DLayerManager.cpp
diff --git a/Source/platform/graphics/Canvas2DLayerManager.cpp b/Source/platform/graphics/Canvas2DLayerManager.cpp
index 4387fce39e27f8e667d40f54f94b376b12e254e2..d4f75755c694fc944b26dfb69692f13c722c3f50 100644
--- a/Source/platform/graphics/Canvas2DLayerManager.cpp
+++ b/Source/platform/graphics/Canvas2DLayerManager.cpp
@@ -28,8 +28,6 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "public/platform/Platform.h"
 #include "wtf/StdLibExtras.h"
 
-using blink::WebThread;
-
 namespace {
 
 enum {
@@ -62,7 +60,7 @@ void Canvas2DLayerManager::init(size_t maxBytesAllocated, size_t targetBytesAllo
     m_maxBytesAllocated = maxBytesAllocated;
     m_targetBytesAllocated = targetBytesAllocated;
     if (m_taskObserverActive) {
-        blink::Platform::current()->currentThread()->removeTaskObserver(this);
+        Platform::current()->currentThread()->removeTaskObserver(this);
         m_taskObserverActive = false;
     }
 }
@@ -81,7 +79,7 @@ void Canvas2DLayerManager::didProcessTask()
 {
     // Called after the script action for the current frame has been processed.
     ASSERT(m_taskObserverActive);
-    blink::Platform::current()->currentThread()->removeTaskObserver(this);
+    Platform::current()->currentThread()->removeTaskObserver(this);
     m_taskObserverActive = false;
     Canvas2DLayerBridge* layer = m_layerList.head();
     while (layer) {
@@ -105,7 +103,7 @@ void Canvas2DLayerManager::layerDidDraw(Canvas2DLayerBridge* layer)
     if (!m_taskObserverActive) {
         m_taskObserverActive = true;
         // Schedule a call to didProcessTask() after completion of the current script task.
-        blink::Platform::current()->currentThread()->addTaskObserver(this);
+        Platform::current()->currentThread()->addTaskObserver(this);
     }
 }
 
@@ -154,5 +152,5 @@ bool Canvas2DLayerManager::isInList(Canvas2DLayerBridge* layer) const
     return layer->prev() || m_layerList.head() == layer;
 }
 
-}
+} // namespace blink