Adding functionality for purgin graphics resource handles

This will allow a fix to WebKit for preventing a crash when the graphics
context is destroyed before the GrContext

BUG=http://code.google.com/p/chromium/issues/detail?id=85309



git-svn-id: http://skia.googlecode.com/svn/trunk@1551 2bbb7eff-a529-9590-31e7-b0007b416f81

gpu/include/GrContext.h

@@ -65,6 +65,13 @@ public:
      */
     void contextLost();
 
+    /**
+     * Similar to contextLost, but makes no attempt to reset state.
+     * Use this method when GrContext destruction is pending, but
+     * the graphics context is destroyed first.
+     */
+    void contextDestroyed();
+
     /**
      * Frees gpu created by the context. Can be called to reduce GPU memory
      * pressure.

gpu/include/GrGpu.h

@@ -325,7 +325,7 @@ public:
      * Called to tell Gpu object that all GrResources have been lost and should
      * be abandoned.
      */
-    void abandonResources();
+    virtual void abandonResources();
 
     /**
      * Called to tell Gpu object to release all GrResources.

gpu/src/GrContext.cpp

@@ -74,6 +74,11 @@ GrContext::~GrContext() {
 }
 
 void GrContext::contextLost() {
+    contextDestroyed();
+    this->setupDrawBuffer();
+}
+
+void GrContext::contextDestroyed() {
     // abandon first to so destructors
     // don't try to free the resources in the API.
     fGpu->abandonResources();
@@ -93,8 +98,6 @@ void GrContext::contextLost() {
     fTextureCache->removeAll();
     fFontCache->freeAll();
     fGpu->markContextDirty();
-
-    this->setupDrawBuffer();
 }
 
 void GrContext::resetContext() {
@@ -1245,8 +1248,10 @@ void GrContext::flushText() {
 
 void GrContext::flushDrawBuffer() {
 #if BATCH_RECT_TO_RECT || DEFER_TEXT_RENDERING
-    fDrawBuffer->playback(fGpu);
-    fDrawBuffer->reset();
+    if (fDrawBuffer) {
+        fDrawBuffer->playback(fGpu);
+        fDrawBuffer->reset();
+    }
 #endif
 }
 

gpu/src/GrGpuGLShaders.cpp

@@ -130,6 +130,11 @@ public:
     }
 };
 
+void GrGpuGLShaders::abandonResources(){
+    INHERITED::abandonResources();
+    fProgramCache->abandon();
+}
+
 void GrGpuGLShaders::DeleteProgram(GrGLProgram::CachedData* programData) {
     GR_GL(DeleteShader(programData->fVShaderID));
     GR_GL(DeleteShader(programData->fFShaderID));

gpu/src/GrGpuGLShaders.h

@@ -31,6 +31,8 @@ public:
 
     virtual void resetContext();
 
+    virtual void abandonResources();
+
 protected:
     // overrides from GrGpu
     virtual bool flushGraphicsState(GrPrimitiveType type);