Allocate bitmaps on the fly for layers

bug:3376517
Change-Id: I68cab08949302dd938b9c4753f9dfebd6c08e298

2 files changed, 27 insertions, 6 deletions

diff --git a/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.cpp b/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.cpp
index 846b9ca..0f2e9f0 100644
--- a/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.cpp
+++ b/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.cpp
@@ -42,6 +42,7 @@ BackedDoubleBufferedTexture::BackedDoubleBufferedTexture(uint32_t w, uint32_t h,
                                                          SkBitmap::Config config)
     : DoubleBufferedTexture(eglGetCurrentContext())
     , m_usedLevel(-1)
+    , m_config(config)
     , m_owner(0)
     , m_busy(false)
 {
@@ -49,21 +50,30 @@ BackedDoubleBufferedTexture::BackedDoubleBufferedTexture(uint32_t w, uint32_t h,
     if (bitmap) {
         m_bitmap = bitmap;
         m_sharedBitmap = true;
+        m_canvas = new SkCanvas(*m_bitmap);
     } else {
+        m_bitmap = 0;
+        m_sharedBitmap = false;
+        m_canvas = 0;
+    }
+}
+
+SkCanvas* BackedDoubleBufferedTexture::canvas()
+{
+    if (!m_bitmap && !m_sharedBitmap) {
         m_bitmap = new SkBitmap();
-        m_bitmap->setConfig(config, w, h);
+        m_bitmap->setConfig(m_config, m_size.width(), m_size.height());
         m_bitmap->allocPixels();
         m_bitmap->eraseColor(0);
+        m_canvas = new SkCanvas(*m_bitmap);
     }
-    m_canvas = new SkCanvas(*m_bitmap);
+    return m_canvas;
 }
 
 BackedDoubleBufferedTexture::~BackedDoubleBufferedTexture()
 {
-    if (!m_sharedBitmap) {
-        m_bitmap->reset();
+    if (!m_sharedBitmap)
         delete m_bitmap;
-    }
     delete m_canvas;
     SharedTexture* textures[3] = { &m_textureA, &m_textureB, 0 };
     destroyTextures(textures);
@@ -116,6 +126,9 @@ bool BackedDoubleBufferedTexture::busy()
 
 void BackedDoubleBufferedTexture::producerUpdate(TextureInfo* textureInfo)
 {
+    if (!m_bitmap)
+        return;
+
     // no need to upload a texture since the bitmap is empty
     if (!m_bitmap->width() && !m_bitmap->height()) {
         producerRelease();
@@ -130,6 +143,13 @@ void BackedDoubleBufferedTexture::producerUpdate(TextureInfo* textureInfo)
         textureInfo->m_height = m_bitmap->height();
     }
 
+    if (!m_sharedBitmap) {
+        delete m_bitmap;
+        delete m_canvas;
+        m_bitmap = 0;
+        m_canvas = 0;
+    }
+
     producerReleaseAndSwap();
 }
 
diff --git a/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.h b/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.h
index 1454d47..eea5807 100644
--- a/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.h
+++ b/WebCore/platform/graphics/android/BackedDoubleBufferedTexture.h
@@ -75,7 +75,7 @@ public:
 
     // private member accessor functions
     TextureOwner* owner() { return m_owner; } // only used by the consumer thread
-    SkCanvas* canvas() { return m_canvas; } // only used by the producer thread
+    SkCanvas* canvas(); // only used by the producer thread
 
     bool busy();
 
@@ -89,6 +89,7 @@ private:
     SkSize m_size;
     SkCanvas* m_canvas;
     int m_usedLevel;
+    SkBitmap::Config m_config;
     TextureOwner* m_owner;
 
     // This values signals that the texture is currently in use by the consumer.